Update labels and issue docs

[lucacome]

Adds new labels to be used across our repos, updates CONTRIBUTING.md and ISSUE_LIFECYCLE.md.

[codecov-commenter]

Codecov Report

Merging #3553 (f0ae4eb) into main (cb20b65) will not change coverage.
The diff coverage is n/a.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@           Coverage Diff           @@
##             main    #3553   +/-   ##
=======================================
  Coverage   51.99%   51.99%           
=======================================
  Files          60       60           
  Lines       16820    16820           
=======================================
  Hits         8746     8746           
  Misses       7777     7777           
  Partials      297      297           

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[ADubhlaoich]

Looks fine, but as best I can tell, the Issue Lifecycle isn't currently linked from anywhere specific (Such as a section of the CONTRIBUTING file).

This means that although the file is navigable, it's not easily discoverable.

[tomasohaodha]

Some labels use hyphens, some use underscores, and some use spaces. It looks inconsistent IMHO - can we standardize?

[lucacome]

@tomasohaodha I've removed the -, the ones with underscores are the ones created (and used) by dependabot