Internationalisation: Add reusable crowdin workflows

[ashharrison90]

Adds reusable crowdin workflows so they can be used across multiple repositories

For https://github.com/grafana/grafana/issues/105659

[ashharrison90]

~josh made a great point - these should probably be composite actions. see:~

• ~https://docs.github.com/en/actions/sharing-automations/reusing-workflows~
• ~https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action~
• ~https://docs.github.com/en/actions/sharing-automations/avoiding-duplication~

edit: actually, i'm back on the reusable workflow train. if these were composite actions, i can't see when we'd ever use them outside of different variations of this workflow in other repos, so let's just make the whole workflow reusable

[github-actions[bot]]

:cry: zizmor failed with exit code 14.

Expand for full output

error[template-injection]: code injection via template expansion
   --> ./.github/workflows/crowdin-download.yml:108:9
    |
108 |         - name: Approve and automerge PR
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this step
109 |           if: steps.crowdin-download.outputs.pull_request_url
...
114 |           # TODO make these paths inputs to the workflow when we move this to a shared repo
115 | /         run: |
116 | |           IFS=$'\n' read -ra CHANGED_ARRAY <<< "$(gh pr diff --name-only ${{ steps.crowdin-download.outputs.pull_request_url }})"
...   |
168 | |           gh pr review ${{ steps.crowdin-download.outputs.pull_request_url }} --approve
169 | |           gh pr merge --auto --squash ${{ steps.crowdin-download.outputs.pull_request_url }}
    | |____________________________________________________________________________________________^ inputs.en_paths may expand into attacker-controllable code
    |
    = note: audit confidence → Low

16 findings (7 ignored, 8 suppressed): 0 unknown, 0 informational, 0 low, 0 medium, 1 high