Refine comments and validation for some config fields

[gavv]

No description provided.

[codecov]

Codecov Report

Merging #118 (378ff7a) into main (7b36e14) will decrease coverage by 0.62%.
The diff coverage is 75.00%.

@@             Coverage Diff              @@
##               main     #118      +/-   ##
============================================
- Coverage     94.80%   94.18%   -0.62%     
- Complexity       80       81       +1     
============================================
  Files            24       24              
  Lines           250      258       +8     
  Branches          2        2              
============================================
+ Hits            237      243       +6     
- Misses            9       10       +1     
- Partials          4        5       +1     

Impacted Files	Coverage Δ
.../org/rocstreaming/roctoolkit/RocContextConfig.java	100.00% <ø> (ø)
...rc/main/java/org/rocstreaming/roctoolkit/Slot.java	100.00% <ø> (ø)
...c/main/java/org/rocstreaming/roctoolkit/Check.java	83.33% <33.33%> (-16.67%)	⬇️
...org/rocstreaming/roctoolkit/RocReceiverConfig.java	100.00% <100.00%> (ø)
...a/org/rocstreaming/roctoolkit/RocSenderConfig.java	100.00% <100.00%> (ø)