SNOW-894815: Fix race conditions and enable TestConcurrentReadOnParams

[sfc-gh-ext-simba-jl]

Description

Issue: https://github.com/snowflakedb/snowflake-sdks-drivers-issues-teamwork/issues/614

Fixes 2 race conditions by adding sync.Mutex locks:

• sc.cfg.Params map is being read in getQueryContextCacheSize() (same fix as Fix concurrent map read and write panic on connection parameter map #706)
• sc.cfg is being read in decodeChunk() while cleanup() is trying to write

Checklist

• Code compiles correctly
• Run make fmt to fix inconsistent formats
• Run make lint to get lint errors and fix all of them
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

[codecov]

Codecov Report

Merging #909 (644b4c0) into master (46bf297) will increase coverage by 0.03%.
Report is 1 commits behind head on master.
The diff coverage is 90.16%.

@@            Coverage Diff             @@
##           master     #909      +/-   ##
==========================================
+ Coverage   83.22%   83.25%   +0.03%     
==========================================
  Files          48       49       +1     
  Lines        9244     9297      +53     
==========================================
+ Hits         7693     7740      +47     
- Misses       1551     1557       +6     

Files	Coverage Δ
chunk_downloader.go	84.09% <100.00%> (ø)
connection.go	84.44% <100.00%> (+0.05%)	⬆️
connection_util.go	86.60% <100.00%> (+0.24%)	⬆️
htap.go	98.03% <100.00%> (+0.16%)	⬆️
rows.go	78.72% <100.00%> (ø)
client_configuration.go	86.04% <86.04%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[sfc-gh-pfus]

Fixed in #926