[Access] Implement integration test for new websockets [WIP]

[UlyanaAndrukhiv]

Closes: #6641, #6876

Note: This PR should be reviewed and merged only after the following PRs are merged:

• [Access] Make response for data providers consistent. #6846
• [Access] Unify subscription id with client message id #6847
• [Access] Add arguments getter for data providers #6873
• [Access] Implement subscribe transaction statuses by transaction ID #6737

Context

This pull request adds integration tests to verify the functionality of the new WebSockets implementation and incorporates the following updates:

1. Fixes from integration test results.
   Errors identified during integration testing have been resolved, ensuring stable and expected behavior for all supported scenarios.

2. Max subscriptions per connection functionality.
   The functionality has been implemented, enforcing a limit on the number of active subscriptions allowed per Websocket connection.

3. Integration test scenarios:

• Happy paths:

  • Subscribing to any topic, ensuring a successful subscription response and expected results.
  • Unsubscribing from a topic successfully.

• Error cases:

  • Attempting to subscribe with invalid data.
  • Attempting to unsubscribe with invalid data.

• Additional behaviors:

  • Retrieving a list of all active subscriptions.
  • Verifying client inactivity tracking and connection loss handling.
  • Verifying the Websockets MaxSubscriptionsPerConnection limits functionality

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 60.88083% with 151 lines in your changes missing coverage. Please review.

Project coverage is 41.01%. Comparing base (ce0396a) to head (fe304e1).

Files with missing lines	Patch %	Lines
.../access/rpc/backend/backend_stream_transactions.go	63.35%	39 Missing and 9 partials ⚠️
engine/access/rest/common/utils.go	47.91%	24 Missing and 1 partial ⚠️
engine/access/rest/websockets/controller.go	58.33%	19 Missing and 1 partial ⚠️
cmd/access/node_builder/access_node_builder.go	0.00%	10 Missing ⚠️
cmd/observer/node_builder/observer_builder.go	0.00%	10 Missing ⚠️
engine/access/rest/util/converter.go	0.00%	8 Missing ⚠️
.../rest/websockets/data_providers/events_provider.go	61.53%	4 Missing and 1 partial ⚠️
...st/websockets/data_providers/mock/data_provider.go	61.53%	2 Missing and 3 partials ⚠️
access/api.go	0.00%	4 Missing ⚠️
...ockets/data_providers/account_statuses_provider.go	72.72%	2 Missing and 1 partial ⚠️
... and 8 more

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6907      +/-   ##
==========================================
- Coverage   41.07%   41.01%   -0.07%     
==========================================
  Files        2120     2121       +1     
  Lines      185958   185987      +29     
==========================================
- Hits        76384    76276     -108     
- Misses     103156   103294     +138     
+ Partials     6418     6417       -1     

Flag	Coverage Δ
unittests	41.01% <60.88%> (-0.07%)	⬇️

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