Make RPC timeout configurable

[codchen]

Describe your changes and provide context

Add a TimeoutRead config for RPC endpoints (read-only)

Testing performed to validate your change

[codecov]

Codecov Report

Attention: Patch coverage is 40.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 58.24%. Comparing base (8484212) to head (d1df601).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #238   +/-   ##
=======================================
  Coverage   58.24%   58.24%           
=======================================
  Files         249      249           
  Lines       34445    34450    +5     
=======================================
+ Hits        20061    20067    +6     
- Misses      12801    12802    +1     
+ Partials     1583     1581    -2     

Files	Coverage Δ
config/config.go	63.11% <100.00%> (+0.13%)	⬆️
config/toml.go	51.35% <ø> (ø)
internal/rpc/core/env.go	18.46% <0.00%> (-0.29%)	⬇️

... and 20 files with indirect coverage changes