Auto merge of #13315 - Phrohdoh:textinput-minlength-13313, r=ConnorGBrewster

Implement minlength attribute for text inputs

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**This is not ready to be merged:
I need help writing tests as I am not familiar with the methods used in the `maxlength` tests (introduced in  tests/unit/script/textinput.rs).**

I also need to write the `minlength-manual` test.

Closes #13313
This depends on #13314 (and includes the commit from it so will need to be rebased once that patch lands).

I am just looking for a quick review to make sure I am on the right path.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #13313

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- [X] There ~~are~~ *will be* tests for these changes

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