feat(input): add styles for ionic theme for fill=solid (#30417)

Issue number: Internal

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## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->
- add fill solid to ionic theme input;
- move input.outline.scss to input.ionic.scss;
- add fill solid to states page;
- remove highlight styles for ionic theme;
- add tests for ionic solid input;

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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  2. Update the BREAKING.md file with the breaking change.
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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->
- fill:
https://ionic-framework-git-rou-11889-ionic1.vercel.app/src/components/input/test/fill?ionic:theme=ionic
- states:
https://ionic-framework-git-rou-11889-ionic1.vercel.app/src/components/input/test/states?ionic:theme=ionic

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Co-authored-by: ionitron <hi@ionicframework.com>