Re-org code (retry)

[jsumners]

This is a replacement for #449 that GH closed and won't let me reopen.

The impetus for this PR was me starting to work on a suggestion PR for #445. When I got into the code, I decided that we have long ago outgrown the structure of the codebase as I created it when splitting this module out of the core Pino module. Basically, it has grown in a difficult to navigate mess with everything crammed into a few large files.

I have more that I intend to do, but I think this PR has become large enough as it is. So I'm halting my work until we make a decision on this (🤞 that means it's merged).

---

This PR is not yet complete as of commit 065fc99. I just want to put it up to show the following:

As of that commit, the "utils" file has been split out into a directory, lib/utils/. This directory has one file per utility function and a corresponding test file for each utility function file. It also updates the tap configuration to include a coverage map. The result is that we are not actually covering at 100% as we assumed:

Coverage Report

❯ tap
Suites:   ​27 passed​, ​27 of 27 completed​
Asserts:  ​​​453 passed​, ​of 453​
ERROR: Coverage for lines (95.48%) does not meet global threshold (100%)
ERROR: Coverage for functions (93.75%) does not meet global threshold (100%)
ERROR: Coverage for branches (85.77%) does not meet global threshold (100%)
ERROR: Coverage for statements (93.29%) does not meet global threshold (100%)
-------------------------------------|---------|----------|---------|---------|-------------------
File                                 | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
-------------------------------------|---------|----------|---------|---------|-------------------
All files                            |   93.29 |    85.77 |   93.75 |   95.48 |                   
 lib                                 |     100 |    90.62 |     100 |     100 |                   
  colors.js                          |     100 |    90.62 |     100 |     100 | 47-48,59          
 lib/utils                           |   92.19 |    84.97 |   91.66 |   94.71 |                   
  build-safe-sonic-boom.js           |   93.75 |    66.66 |   66.66 |   93.75 | 21                
  create-date.js                     |     100 |      100 |     100 |     100 |                   
  delete-log-property.js             |     100 |       80 |     100 |     100 | 24                
  filter-log.js                      |     100 |      100 |     100 |     100 |                   
  format-time.js                     |   95.23 |    93.33 |     100 |   95.23 | 45                
  get-property-value.js              |     100 |      100 |     100 |     100 |                   
  handle-custom-levels-names-opts.js |    92.3 |    71.42 |     100 |     100 | 18,24             
  handle-custom-levels-opts.js       |    92.3 |    71.42 |     100 |     100 | 18,24             
  interpret-conditionals.js          |     100 |      100 |     100 |     100 |                   
  is-object.js                       |     100 |      100 |     100 |     100 |                   
  is-valid-date.js                   |     100 |      100 |     100 |     100 |                   
  join-lines-with-indentation.js     |     100 |      100 |     100 |     100 |                   
  noop.js                            |     100 |      100 |     100 |     100 |                   
  prettify-error-log.js              |   38.46 |    46.15 |   33.33 |   45.45 | 48-69             
  prettify-error.js                  |     100 |      100 |     100 |     100 |                   
  prettify-level.js                  |     100 |    83.33 |     100 |     100 | 39                
  prettify-message.js                |     100 |      100 |     100 |     100 |                   
  prettify-metadata.js               |     100 |     87.5 |     100 |     100 | 28,32,43,50       
  prettify-object.js                 |   94.28 |    73.33 |     100 |     100 | 52,60,74-105      
  prettify-time.js                   |     100 |    91.66 |     100 |     100 | 45                
  split-property-key.js              |     100 |      100 |     100 |     100 |                   
-------------------------------------|---------|----------|---------|---------|-------------------

Okay, so that's not quite true. The difference is that some of the coverage comes through the factory function tests. With the restructure we have 1:1 test to code and we can see the gaps. it is my opinion that we should be able to recognize that file Y covers code X. Prior to this PR, one has to dig through a lot of code to find where something might be covering the code in question. As an example, in order to properly cover a case in handle-custom-levels-opts and handle-custom-levels-names-opts I had to read back through the git blame and learn what code was added to cover an odd branch.

---

After rebasing this on #451, I get numbers like this for the changes in this PR:

basicLog*10000: 759.376ms
objectLog*10000: 619.476ms
coloredLog*10000: 731.759ms
customPrettifiers*10000: 724.363ms
logWithErrorObject*10000: 561.199ms
logRemappedMsgErrKeys*10000: 556.772ms
messageFormatString*10000: 924.174ms
basicLog*10000: 726.8ms
objectLog*10000: 609.106ms
coloredLog*10000: 725.651ms
customPrettifiers*10000: 722.982ms
logWithErrorObject*10000: 562.306ms
logRemappedMsgErrKeys*10000: 561.282ms
messageFormatString*10000: 968.223ms

So, roughly no change in performance by splitting the functions out into their own files/scopes.

[mcollina]

rubberstamp lgtm