Fix/1408 more consistent UI timer

[seyfeb]

Topic and Scope

• Update timer display
  • Remove H:MM from label
  • Add units
  • Add support for durations with seconds
• Add possibility to define seconds for time periods in recipe editor
• Make global i18n n(...) function available in JS

Closes #1408. Closes #1747

Concerns/issues

This currently only supports translations to left-to-right languages, i.e., first hours, then minutes, then seconds.

Formal requirements

There are some formal requirements that should be satisfied. Please mark those by checking the corresponding box.

• I did check that the app can still be opened and does not throw any browser logs
• I created tests for newly added PHP code (check this if no PHP changes were made)
• I updated the OpenAPI specs and added an entry to the API changelog (check if API was not modified)
• I notified the matrix channel if I introduced an API change

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (f2ae69a) 80.07% compared to head (2d921ff) 80.07%.
Report is 3 commits behind head on master.

❗ Current head 2d921ff differs from pull request most recent head 7b55fb0. Consider uploading reports for the commit 7b55fb0 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2014   +/-   ##
=======================================
  Coverage   80.07%   80.07%           
=======================================
  Files          92       92           
  Lines        2650     2650           
=======================================
  Hits         2122     2122           
  Misses        528      528           

Flag	Coverage Δ
integration	21.43% <ø> (ø)
migration	5.69% <ø> (ø)
unittests	57.09% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[github-actions]

Test Results

   12 files    572 suites   1m 30s ⏱️
  552 tests   552 ✅ 0 💤 0 ❌
2 208 runs  2 207 ✅ 1 💤 0 ❌

Results for commit 948e229.

♻️ This comment has been updated with latest results.

[christianlupus]

Looks good. I have not verified every single line but it seems o work out well.