fix(GLTokenSelector): move text input specific HTML attributes from container to text input

What does this MR do?

There are a few useful HTML attributes that should be on the text input instead of the token selector wrapper. This adds props for autocomplete, aria-labelledby and placeholder and adds those attributes to the text input.

Screenshots

autocomplete is the only attribute that causes a visual change:

No tokens selected

Tokens selected

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines.
• GitLab UI's contributing guidlines.
• [-] If it changes a Pajamas-compliant component's look & feel, the MR has been reviewed by a UX designer.
• [-] If it changes GitLab UI's documentation guidelines, the MR has been reviewed by a Technical Writer.
• [-] If the MR changes a component's API, integration MR(s) have been opened in the following projects to ensure that the @gitlab/ui package can be upgraded quickly after the changes are released:
  • GitLab: mr_url
  • Customers Portal: mr_url
  • Status Page: mr_url
• Added the ~"component:*" label(s) if applicable.