fix(editor): don't respect default calendar in the calendar picker

[st3iny]

Ref #5942
Partially reverts #5790

The default calendar URL from the backend is more restrictive as it is primarily meant for incoming invitations. This commit effectively reverts the editor's calendar picker default choice to how it behaved before v4.7.0.

As discussed in a meeting with Christoph.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 23.51%. Comparing base (397c78e) to head (4f2caf6).
Report is 2 commits behind head on main.

Files	Patch %	Lines
src/components/AppNavigation/Settings.vue	0.00%	2 Missing ⚠️
src/store/calendarObjects.js	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #5996   +/-   ##
=========================================
  Coverage     23.51%   23.51%           
  Complexity      455      455           
=========================================
  Files           246      246           
  Lines         11722    11718    -4     
  Branches       2156     2154    -2     
=========================================
  Hits           2756     2756           
+ Misses         8650     8647    -3     
+ Partials        316      315    -1     

Flag	Coverage Δ
javascript	15.16% <0.00%> (+<0.01%)	⬆️
php	58.46% <ø> (ø)

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[st3iny]

Backport is tricky due to translation changes.

[rakekniven]

For calendar power users, it is inconvenient to select a calendar every time or it is easy to forget.
Example: We have a family calendar. This is the third in the list. The first one is the waste calendar.
Since the change, a good 50% of the appointments we create end up in the waste calendar.

@st3iny fyi