Improve translations

[carstingaxion]

Description of the Change

This PR fixes four little bugs according to the translation handling of some strings.

1. Dateformat of datetime block is not translated/translatable
   I think @patriciabt mentioned this as well. Not sure if a ticket was created though.
   (from Purpose, bug or room for enhancements #557)

2. Allow for easier translation #551
3. Allow for easier translation #551
4. Allow for easier translation #551

Closes #551

How to test the Change

Changes can be seen & tested, when the translations are updated, so every translation contributor is happily invited to:

1. Update their .po files from the updated .pot file
2. Update and add translations
3. Run npm run i18n:json
4. Run npm run i18n:php

(This should be an issue, on its own ... i feel it)

Changelog Entry

Fixed - Render translated version of date-time-block also within the editor and simplify translation of (some) strings

Credits

Props @carstingaxion

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[what-the-diff]

PR Summary

• Update of date and time translation string in edit.js
  The translation string used for displaying date and time format in the edit.js file located in src/blocks/event-date was modified. The updated string now includes the word 'gatherpress', improving the clarity of data displayed.

This change will contribute to a clearer display of date and time information, improving the overall usage experience.

[carstingaxion]

I'm really sorry for this messed up commit history. May the git god forgive me.

[mauteri]

Looks good, thanks!