chore_: rename integration tests to functional tests

[igor-sirotin]

1. As agreed, rename the RPC tests from integration to functional.
2. The directory is named tests-functional (not funcitonal-tests), so that we could create real tests-integration at some point later.

[status-im-auto]

Jenkins Builds

❔	Commit	#️⃣	Finished (UTC)	Duration	Platform	Result
✔️	94e9628	#1	2024-10-03 13:19:07	~4 min	tests-rpc	📄log
✔️	94e9628	#1	2024-10-03 13:19:21	~4 min	linux	📦zip
✔️	94e9628	#1	2024-10-03 13:19:33	~4 min	ios	📦zip
✔️	94e9628	#1	2024-10-03 13:20:24	~5 min	android	📦aar
✔️	94e9628	#1	2024-10-03 13:48:03	~32 min	tests	📄log

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 46.10%. Comparing base (04784d1) to head (94e9628).
Report is 1 commits behind head on develop.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5908      +/-   ##
===========================================
+ Coverage    45.42%   46.10%   +0.68%     
===========================================
  Files          891      891              
  Lines       158084   158082       -2     
===========================================
+ Hits         71808    72883    +1075     
+ Misses       78201    76841    -1360     
- Partials      8075     8358     +283     

Flag	Coverage Δ
functional	11.85% <ø> (?)
unit	45.50% <ø> (+0.08%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 135 files with indirect coverage changes