fix: change mutex to rwLock and fix relay unsubscribe

[chaitanyaprem]

Description

While going through relay code, noticed that topicMutex could be made rwMutex. Unsubscribing from a topic flow is not protected by this mutex which could cause data race.

Changes

• Changed topicMutex to RWMutex
• Protecting subscriptionsMap and topicsMap during usubscribe.
• Added few tests to cover unsubscribe and other relay functions

Tests

Ran all tests with and without race flag.

[status-im-auto]

Jenkins Builds

Click to see older builds (12)

❔	Commit	#️⃣	Finished (UTC)	Duration	Platform	Result
✖️	982848c	#1	2023-09-18 05:22:01	~18 sec	nix-flake	📄log
✔️	982848c	#1	2023-09-18 05:24:05	~2 min	linux	📦deb
✔️	982848c	#1	2023-09-18 05:24:37	~2 min	tests	📄log
✔️	982848c	#1	2023-09-18 05:24:49	~3 min	tests	📄log
✔️	982848c	#1	2023-09-18 05:25:27	~3 min	android	📦tgz
✔️	982848c	#1	2023-09-18 05:26:37	~4 min	ios	📦tgz
✖️	5d32705	#2	2023-09-18 06:57:52	~17 sec	nix-flake	📄log
✔️	5d32705	#2	2023-09-18 06:58:33	~59 sec	linux	📦deb
✔️	5d32705	#2	2023-09-18 07:00:27	~2 min	tests	📄log
✔️	5d32705	#2	2023-09-18 07:00:35	~2 min	tests	📄log
✔️	5d32705	#2	2023-09-18 07:01:17	~3 min	ios	📦tgz
✔️	5d32705	#2	2023-09-18 07:01:19	~3 min	android	📦tgz

❔	Commit	#️⃣	Finished (UTC)	Duration	Platform	Result
✔️	5218438	#3	2023-09-18 08:38:19	~1 min	linux	📦deb
✔️	5218438	#3	2023-09-18 08:38:31	~1 min	tests	📄log
✔️	5218438	#3	2023-09-18 08:39:02	~1 min	tests	📄log
✔️	5218438	#3	2023-09-18 08:39:14	~2 min	nix-flake	📄log
✔️	5218438	#3	2023-09-18 08:40:23	~3 min	android	📦tgz
✔️	5218438	#3	2023-09-18 08:41:30	~4 min	ios	📦tgz
✔️	9fef06a	#4	2023-09-18 11:56:01	~5 min	tests	📄log
✔️	9fef06a	#4	2023-09-18 11:56:22	~5 min	linux	📦deb
✔️	9fef06a	#4	2023-09-18 11:56:25	~5 min	nix-flake	📄log
✔️	9fef06a	#4	2023-09-18 11:58:00	~7 min	android	📦tgz
✔️	9fef06a	#4	2023-09-18 11:58:01	~7 min	tests	📄log
✔️	9fef06a	#4	2023-09-18 12:02:39	~11 min	ios	📦tgz