fix: Add brute force protection to form endpoints

[susnux]

Endpoints that query for forms are now protected against brute force attacks to find valid forms, invalid hashes or IDs.

[codecov]

Codecov Report

Attention: Patch coverage is 46.00000% with 27 lines in your changes missing coverage. Please review.

Project coverage is 43.40%. Comparing base (6ee4774) to head (4203396).
Report is 16 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2269      +/-   ##
============================================
- Coverage     43.40%   43.40%   -0.01%     
- Complexity      881      882       +1     
============================================
  Files            75       77       +2     
  Lines          3361     3359       -2     
============================================
- Hits           1459     1458       -1     
+ Misses         1902     1901       -1     

[Chartman123]

Could you perhaps base this on my api PR?

[Chartman123]

@susnux thanks to @provokateurin we could finally merge the OpenAPI PR, so I think that you can now go on with this PR and base it on the current main

[susnux]

@Chartman123 rebased and adjusted to the new controller

[Chartman123]

Should we add the brute force protection to the page controller for public share hashes too?

[provokateurin]

Changes look good, but I have little knowledge about the Forms app, so I have to leave it to someone else.

[Chartman123]

Should be fine now :) Just squash the commits and then we're good to go. And we can add the protection in the PageController in a follow-up :)