Refactor userland pages

[MaHaWo]

• removes much of the old datastructures
• makes more use of runes
• adds a small DateInput data input component
• updates fileupload component
• rebuilds userregistration with #await block

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 191 lines in your changes missing coverage. Please review.

Project coverage is 26.83%. Comparing base (24cb0af) to head (d8c4f74).

Files with missing lines	Patch %	Lines
frontend/src/lib/components/UserDataInput.svelte	0.00%	59 Missing :warning:
...rontend/src/lib/components/UserRegistration.svelte	0.00%	36 Missing :warning:
...tend/src/lib/components/DataInput/DataInput.svelte	0.00%	32 Missing and 1 partial :warning:
...end/src/lib/components/DataInput/Fileupload.svelte	0.00%	17 Missing and 1 partial :warning:
frontend/src/lib/components/UserLogin.svelte	0.00%	17 Missing :warning:
frontend/src/lib/components/UserProfile.svelte	0.00%	9 Missing :warning:
...tend/src/lib/components/DataInput/DateInput.svelte	0.00%	7 Missing and 1 partial :warning:
frontend/src/lib/components/UserLandingPage.svelte	0.00%	7 Missing :warning:
.../lib/components/Admin/EditUserQuestionModal.svelte	0.00%	3 Missing :warning:
frontend/src/lib/stores/componentStore.ts	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #144 +/- ## ========================================== + Coverage 26.34% 26.83% +0.48% ========================================== Files 92 93 +1 Lines 3519 3455 -64 Branches 121 122 +1 ========================================== Hits 927 927 + Misses 2526 2461 -65 - Partials 66 67 +1 ```

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[MaHaWo]

included comments. merging asap

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud