Update languages field to use SearchSelectorField

[twilkhoo]

Ticket link

Closes #591, #666

Implementation description

• Replaced SelectorField with SearchSelectorField for languages in the AccountForm, and added all necessary dependencies, very similar to the skills SearchSelectorField implementation

Steps to test

1. Login as a volunteer or employee
2. Navigate to the Edit Profile page and test the languages field
3. Note: You won't be able to actually submit the changes if using the Firebase hosting link below since that does not include the backend changes in the preview. Testing locally works fine.

What should reviewers focus on?

• Correctness
• Similarity with the SearchSelectorField for adding skills
• Ensuring all code for the languages field implementation doesn't still say "skills" anywhere

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[twilkhoo]

This just clears input when a user selects something from the dropdown.

[github-actions]

Visit the preview URL for this PR (updated for commit 1237c15):

https://sistering-dev--pr667-tejas-update-languag-exofdmlf.web.app

_{(expires Tue, 06 Sep 2022 18:47:29 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[MatoPlus]

Code looks good. I'll test this out in a bit and approve.

[MatoPlus]

LGTM, thanks for adding this in. Huge UX improvement 😤