[Remove Vuetify from Studio] Collection name input and validation in Channels

[AadarshM07]

Summary

Removed Vuetify from the collection name input on the Channels > New Collection page , and updated the validation logic to generateFormMixin .

Verified that the text box still supports the following features:

• Character counter
• maxlength enforcement
• Proper error message display in invalid cases

Screenshots:

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References

Closes #5298

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Reviewer guidance

In the previous Vuetify textbox behavior, the "Field is required" message appeared when submitting without input and disappeared once the textbox was focused again.
In the current KTextbox, the error message does not disappear on focus after being triggered.
I checked the KTextbox documentation and couldn’t find any prop that controls this behavior - if this is not the right approach, suggestions would be helpful.

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[AadarshM07]

I'll look into the failing workflow 👍