(CODEMGMT-1294) Resync repos with unresolvable refs

[jarretlavallee]

Prior to this commit, if the git repo did not have a valid HEAD or the
ref was not resolvable, r10k would raise an error and fail. This commit
changes the behavior to do a forceful resync of the git repo.
This commit updates the status method for stateful git repos to return
:mismatched when the repo.head is nil. This commit updates the resolve
method for rugged base repositories to catch Rugged::OdbError, which
would have resulted in object not found - no match for id messages.
This condition would occur when the local repo was out of sync with the
upstream repo and a local commit could not be found in the upstream
repo. Since this condition indicates that the repo has diverged from the
upstream repository, this change forces a full resync of the git repo to
ensure it is in sync.

[jarretlavallee]

A simple repo:

# /etc/puppetlabs/r10k/r10k.yaml
:cachedir: '/var/cache/r10k'
git:
  provider: rugged
:sources:
  :local:
    remote: file:///opt/repos/r10k
    basedir: '/etc/puppetlabs/code/environments'

# mkdir -p /opt/repos/
# git clone https://github.com/puppetlabs/control-repo.git /opt/repos/r10k
# /opt/puppetlabs/puppet/bin/r10k deploy environment -v -p
# GIT_SEQUENCE_EDITOR='sed -i ''0,/^pick/!{s/^pick/fixup/}''' git rebase -i HEAD~2
# rm -rf /var/cache/r10k/
# /opt/puppetlabs/puppet/bin/r10k deploy environment -v debug2 -p 

With this PR, debug2 shows the Unable to resolve HEAD: object not found - no match for id and the repo is forcefully resynced: [2021-11-02 13:44:01 - DEBUG] Replacing /etc/puppetlabs/code/environments/main and checking out main

# GIT_SEQUENCE_EDITOR='sed -i ''0,/^pick/!{s/^pick/fixup/}''' git rebase -i HEAD~2
[detached HEAD 4b3b92b] Rename winscript.ps1 to win.ps1
Successfully rebased and updated refs/heads/main.
# rm -rf /var/cache/r10k/
# /opt/puppetlabs/puppet/bin/r10k deploy environment -v debug2 -p 
...
[2021-11-02 13:44:01 - DEBUG] Fetching 'file:///opt/repos/r10k' to determine current branches.
[2021-11-02 13:44:01 - DEBUG1] Creating new git cache for "file:///opt/repos/r10k"
[2021-11-02 13:44:01 - DEBUG1] Cloning 'file:///opt/repos/r10k' into /var/cache/r10k/file----opt-repos-r10k
[2021-11-02 13:44:01 - DEBUG1] Fetching remote 'origin' at /var/cache/r10k/file----opt-repos-r10k
[2021-11-02 13:44:01 - DEBUG2] Transferred 918 objects (139041 bytes) from 'origin' into /var/cache/r10k/file----opt-repos-r10k'
[2021-11-02 13:44:01 - DEBUG2] Unable to resolve HEAD: object not found - no match for id (aa9fbf40c0fa901a1a68053340a8d8b80b28177c) 
[2021-11-02 13:44:01 - INFO] Deploying environment /etc/puppetlabs/code/environments/main
[2021-11-02 13:44:01 - DEBUG2] Unable to resolve HEAD: object not found - no match for id (aa9fbf40c0fa901a1a68053340a8d8b80b28177c) 
[2021-11-02 13:44:01 - DEBUG] Replacing /etc/puppetlabs/code/environments/main and checking out main
[2021-11-02 13:44:01 - DEBUG1] Cloning 'file:///opt/repos/r10k' into /etc/puppetlabs/code/environments/main
[2021-11-02 13:44:01 - DEBUG2] Checking out ref '4b3b92bfa1c2829c14b5625a095afcc9b212a615' (resolved to SHA '4b3b92bfa1c2829c14b5625a095afcc9b212a615') in repository /etc/puppetlabs/code/environments/main
[2021-11-02 13:44:01 - INFO] Environment main is now at 4b3b92bfa1c2829c14b5625a095afcc9b212a615
[2021-11-02 13:44:01 - INFO] Using Puppetfile '/etc/puppetlabs/code/environments/main/Puppetfile'
[2021-11-02 13:44:01 - DEBUG] Using moduledir '/etc/puppetlabs/code/environments/main/modules'
[2021-11-02 13:44:01 - DEBUG] Purging unmanaged Puppetfile content for environment 'main'...
[2021-11-02 13:44:01 - DEBUG1] No unmanaged contents in , nothing to purge
[2021-11-02 13:44:01 - DEBUG] Purging unmanaged environments for deployment...
[2021-11-02 13:44:01 - DEBUG1] Fetching remote 'origin' at /var/cache/r10k/file----opt-repos-r10k
[2021-11-02 13:44:01 - DEBUG2] Transferred 0 objects (0 bytes) from 'origin' into /var/cache/r10k/file----opt-repos-r10k'
[2021-11-02 13:44:01 - DEBUG1] Source local in /etc/puppetlabs/code/environments manages contents ["main"]
[2021-11-02 13:44:01 - DEBUG1] No unmanaged contents in /etc/puppetlabs/code/environments, nothing to purge