Merge #13126: util: Add Clang thread safety annotations for variables guarded by cs_args

Summary:
1e29379d69 Fix potential deadlock (practicalswift)
d58dc9f943 Add lock annotations (cs_args) (practicalswift)
db5e9d3c88 Add missing locks (cs_args) (practicalswift)

Pull request description:

• Add missing cs_args locks
• Add Clang thread safety annotations for variables guarded by cs_args

Tree-SHA512: bc562dbddf24a287bcf9bf902bc930f942f260a94e5c8ec4d190f7f2ddac448ed3d52acadaf9fc1c81a5cbff2c171c52c18ba0804eeb03f699d70394e1c977c5

Backport of Core PR13126
https://github.com/bitcoin/bitcoin/pull/13126/

Completes T652

Test Plan:

cmake -GNinja .. -DENABLE_WERROR=ON
ninja check

Also run build-werror and build-tsan builds.

Reviewers: deadalnix, Fabien, jasonbcox, O1 Bitcoin ABC, #bitcoin_abc, markblundeberg

Reviewed By: jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Subscribers: markblundeberg

Differential Revision: https://reviews.bitcoinabc.org/D4965