fix_: fetch curated communities sequentially

[igor-sirotin]

Description

1. Replaced parallel communities fetching with sequential. Fetching many communities in parallel unneccesarily overloads the backend when creating a new account. Fetching them one by one is absolutely acceptable.
2. Removed the now unused FetchCommunities function.

[status-im-auto]

Jenkins Builds

❔	Commit	#️⃣	Finished (UTC)	Duration	Platform	Result
✔️	3cbeea8	#1	2025-06-09 11:02:26	~2 min	android	📦aar
✔️	3cbeea8	#1	2025-06-09 11:02:28	~2 min	macos	📦zip
✔️	3cbeea8	#1	2025-06-09 11:02:55	~3 min	linux	📦zip
✔️	3cbeea8	#1	2025-06-09 11:04:59	~5 min	macos	📦zip
✔️	3cbeea8	#1	2025-06-09 11:05:22	~5 min	windows	📦zip
✔️	3cbeea8	#1	2025-06-09 11:06:10	~6 min	ios	📦zip
✖️	3cbeea8	#1	2025-06-09 11:07:43	~8 min	tests-rpc	📄log
✔️	3cbeea8	#1	2025-06-09 11:10:21	~10 min	linux	📦zip
✔️	3cbeea8	#1	2025-06-09 11:25:13	~25 min	tests	📄log
✔️	0143865	#2	2025-06-09 13:46:33	~2 min	android	📦aar
✔️	0143865	#2	2025-06-09 13:47:00	~2 min	macos	📦zip
✔️	0143865	#2	2025-06-09 13:47:12	~3 min	linux	📦zip
✔️	0143865	#2	2025-06-09 13:49:27	~5 min	macos	📦zip
✔️	0143865	#2	2025-06-09 13:49:59	~6 min	ios	📦zip
✔️	0143865	#2	2025-06-09 13:51:38	~7 min	tests-rpc	📄log
✔️	0143865	#2	2025-06-09 13:51:44	~7 min	windows	📦zip
✔️	0143865	#2	2025-06-09 13:53:53	~9 min	linux	📦zip
✔️	0143865	#2	2025-06-09 14:11:14	~27 min	tests	📄log
✔️	0143865	#3	2025-06-09 18:32:44	~24 min	tests	📄log

[codecov]

Codecov Report

Attention: Patch coverage is 9.09091% with 10 lines in your changes missing coverage. Please review.

Project coverage is 60.50%. Comparing base (b6bc172) to head (0143865).
Report is 5 commits behind head on develop.

Files with missing lines	Patch %	Lines
protocol/messenger_curated_communities.go	9.09%	10 Missing ⚠️

❌ Your patch status has failed because the patch coverage (9.09%) is below the target coverage (50.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #6649      +/-   ##
===========================================
+ Coverage    60.44%   60.50%   +0.05%     
===========================================
  Files          839      839              
  Lines       104266   104264       -2     
===========================================
+ Hits         63022    63083      +61     
+ Misses       33656    33624      -32     
+ Partials      7588     7557      -31     

Flag	Coverage Δ
functional	25.57% <9.09%> (-0.12%)	⬇️
unit	58.38% <9.09%> (+0.04%)	⬆️

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

Files with missing lines	Coverage Δ
protocol/messenger_communities.go	52.42% <ø> (+0.06%)	⬆️
protocol/messenger_store_node_request_manager.go	58.11% <ø> (+1.90%)	⬆️
protocol/messenger_curated_communities.go	29.47% <9.09%> (-1.93%)	⬇️

... and 42 files with indirect coverage changes

[osmaczko]

👍