Update Zowe VSCode extension

[JTonda]

As Michelle, I want the Zowe VSCode Extension to work properly with profiles stored in plain text so that I can continue to make use of it to improve my interaction with z/OS datasets.

Update Zowe VSCode extension to work with profile credentials now stored in plain text under .zowe. Update documentation. No requirement to also work with securely stored profiles (eg 1.x).

Enhance error message to say that version is incompatible, please upgrade to the latest version. See comment below.

Depends on zowe/zowe-cli#7
'Replace Keytar - Store creds in plain text' in Zowe CLI repo

• Bump versions of zowe and imperative
  Status: Completed
  Assigned: @AHumanFromCA

• Remove calls to CredentialManager and keytar
  Status: Completed
  Assigned: @AHumanFromCA

• Initialize logger to prevent possible problems
  Status: Completed
  Assigned: @lyzla01

• Modify CliProfileManager calls to account for plaintext credentials
  Status: It just worked without any changes :)
  Assigned:

• Run system tests
  Status: Completed
  Assigned: @AHumanFromCA

• Update documentation
  Status:
  Assigned: @JamesBauman

*Accept feature with PM when complete (This & zowe/zowe-cli#16 both in this Sprint)
8 point story

[ghost]

Meeting Notes

• Remove calls to CredentialManager / keytar
• Initialize the logger
• Possible updates to CliProfileManager call to account for no credential manager
• Update documentation
  • Remove doc about keytar
• Publish via pipeline not part of this story
• Bump version of zowe and imperative
• Run existing system tests. They should all pass

[ghost]

After further discussions this ask might be impossible:

Enhance error message to say that version is incompatible, please upgrade to the latest version.

Reasons

• The meta file for profiles does not contain any versioning information
• The new system can work without zowe-cli being installed as all profiles can be hand created

Notes:

• As is currently, if there are missing properties, the CliProfileManager will inform of the missing fields

Command Error:
Expect Error: Required parameter 'hostname' must be defined

[ghost]

At this point, the story wasn't to enable plaintext profiles. I think the actual story should be more like, bring VSC Extension to production quality :/