refactor(form-mixin): Refactor form components for native behavior alignment

[rkaraivanov]

• Aligned form components to mimic native counterparts when setting value/checked states via setAttribute(), ensuring internal defaultValue is updated accordingly.
• Removed obsolete code.
• Consolidated code into a more efficient API.
• Renamed internal methods for clarity.

Closes #1386

[rkaraivanov]

@wnvko
Feel free to test more form components if you have the time 😁

[wnvko]

@radomirchev
Rating with no initial value does not reset after user selects some value. Having rating in form like this:

<form action="">
  <igc-rating name="my-rating"></igc-rating>
  <igc-button type="reset">Reset</igc-button>
</form>

If I choose some value and then click reset button nothing happens - rating retains its value. This bug does not happen if rating has initial value, or if rating is single.

[rkaraivanov]

@radomirchev Rating with no initial value does not reset after user selects some value. Having rating in form like this:

<form action="">
  <igc-rating name="my-rating"></igc-rating>
  <igc-button type="reset">Reset</igc-button>
</form>

If I choose some value and then click reset button nothing happens - rating retains its value. This bug does not happen if rating has initial value, or if rating is single.

@wnvko
I suppose that replay was for me.
Thanks for catching the issue, it should be fixed now.