Add language support for Go workspaces

[goto1134]

Description

Adds support for Go workspace (go.work) files.

Checklist:

• I am adding a new extension to a language.

  • The new extension is used in hundreds of repositories on GitHub.com
    • Search results for each extension:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3Ago.work.sum
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/portainer/portainer/blob/develop/go.work.sum
    • Sample license(s): zlib License
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

• I am adding a new language.

  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A%2F%28%5E%7C%5C%2F%29go%5C.work%24%2F
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/portainer/portainer/blob/develop/go.work
    • Sample license(s): zlib License
  • I have included a syntax highlighting grammar: [URL to grammar repo]
  • I have added a color
    • Hex value: #00ADD8
    • Rationale: To match other Go language files
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

LGTM. Thanks.

Note: this PR will not be merged until close to when the next release is made. See here for more details.