feat: distributed requests synchronization

[mirkoSekulic]

Description

Before this pr, in-memory UserRequestsSynchronizationService solution was used to synchronize parallel requests.
The solution was designed only to support one replica.

The solution is replaced in pr to support distributed locking.

Generic RequestSynchronizationMiddleware was added and designed to synchronize user requests in a distributed environment, ensuring that concurrent requests are handled without conflicts.

All explicit locking code is removed from controllers and services.

The logic for determining which endpoints will be synchronized is in the EndpointNameSyncEvaluator class.
The solution is flexible to add a new endpoint to synchronization.
The existing EndpointNameSyncEvaluator class can be used, or another class implementing IRequestSyncEvaluator can be added to the project and it will be auto-registered.

Under the hood PosstgreSql advisory locks are used to synchronize requests.
A file system is used for synchronization in the unit tests.
Gitea integration tests and Playwright tests are using advisory locks.

Related Issue(s)

• #{issue number}

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)

Documentation

• User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.20%. Comparing base (c9d1e52) to head (4ae1b52).

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13993   +/-   ##
=======================================
  Coverage   95.20%   95.20%           
=======================================
  Files        1740     1740           
  Lines       22815    22815           
  Branches     2670     2670           
=======================================
  Hits        21722    21722           
  Misses        847      847           
  Partials      246      246           

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[mlqn]

Tested OK in dev! 🚀