fix!: Unify icon usage

[werdnanoslen]

Summary

Addresses these two ACs in the original issue:

• Double check our components are using the correct uswds icons. GovBanner uses a lock icon for example.
• Replace usage of icons in our components with our react-uswds .

Related Issues or PRs

Resolves #1303

How To Test

Confirm that all SVGs still in use are for images that aren't icons

Screenshots (optional)

N/A, looks the same visually, and behaves the same with some attribute changes

[brandonlenz]

There's some Happo diffs, in particular SocialLinks which I think needs adjustment before merge:

The icon used in the search component reduces the size pretty noticeably from what we previously had, which I think deviates far enough from the USWDS examples to call out (Looks like its a safari thing though 🤔):

Since this PR removes a consumer-facing component, it'll be a breaking change. Nothing to worry about with that, but you should update the title to add a ! after fix so that our release process properly bumps our major version on the next release based on the conventional commit spec

[werdnanoslen]

Social links I wasn't sure if it needed to change per se, given the styles referenced there turn it black based on its parent div (medium/big footers) and USWDS site doesn't define their style directly. So since our implementation uses their styles, they are sort of 'supposed' to be blue out of their context, since they're links. I think 🤷

I'll fix the mobile search icon bug though, I left out the size attr

[werdnanoslen]

@brandonlenz are Happo diffs approvable?

[gidjin]

LGTM, left a question but it's not blocking.

[gidjin]

Question: Should these have alt tags too?

[werdnanoslen]

no, the alt prop only applies to <img>. Now that it's an <svg>, I have a line at the bottom of that block to check the name prop instead, which serves the same purpose.