[fix]: Disable submit button on invalid minDuration or maxDuration

[hari45678]

Which problem is this PR solving?

• part of [Bug]: Fix regressions on SearchTracePage form #2599

Description of the changes

• This PR fixes a minor bug that allows the submit button to be clicked even when entered duration in minDuration or maxDuration is invalid.
• I have also changed a few variable names as per comments [1] & [2]

How was this change tested?

• manually using npm run start and automated tests

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• I have run lint and test steps successfully
  • for jaeger: make lint test
  • for jaeger-ui: npm run lint and npm run test

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.61%. Comparing base (657cd00) to head (277bec7).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2600   +/-   ##
=======================================
  Coverage   96.61%   96.61%           
=======================================
  Files         255      255           
  Lines        7744     7745    +1     
  Branches     1998     1935   -63     
=======================================
+ Hits         7482     7483    +1     
  Misses        262      262           

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[yurishkuro]

Thanks!