Use smaller and compressed varients of buttons and form components

[AMoo-Miki]

Description

Replace instances of EuiButton that don't have an explicit sizing attribute to EuiSmallButton*. Replace instances of Eui<form elements> that don't have density attributes to EuiCompressed<form elements>.

Check List

• [ ] New functionality includes testing.
  • [ ] All tests pass
• [ ] New functionality has been documented.
• [X] Commits are signed per the DCO using --signoff

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[AMoo-Miki]

Btw, is there any standardized guidelines for this listed somewhere I can reference for the future?

Viraj owns it. Can't tag him here somehow.