fix: [SECURESIGN-687] endpoint sanitization

[kahboom]

This PR fixes an issue (SECURESIGN-687) with the Rekor endpoint configuration in the Settings modal, where pressing Enter would trigger a page refresh, skipping validation and not persisting the value.

Changes:

• Add validation function to check for invalid characters, string length, and protocol
• Remove check for tld and dot in endpoint
• Add form submission handler with preventDefault() to prevent default form submission behavior
• Add an onSubmit attribute to the Form component to handle the form submission event
• Add handle submit button to allow the form to be submitted with enter key
• Update tests to reflect new changes
• Fix an issue with Cypress type checking being overridden by Jest type checking

The video below shows the form now properly being validated and/or submitted on pressing the Enter key.

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 3 lines in your changes missing coverage. Please review.

Project coverage is 65.04%. Comparing base (d80daa3) to head (29fb678).

Files	Patch %	Lines
src/modules/components/Settings.tsx	76.92%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #112      +/-   ##
==========================================
+ Coverage   65.00%   65.04%   +0.03%     
==========================================
  Files          14       14              
  Lines        1583     1599      +16     
  Branches       58       58              
==========================================
+ Hits         1029     1040      +11     
- Misses        553      558       +5     
  Partials        1        1              

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[lance]

/lgtm