chore: clean up dependencies

[with-heart]

This PR makes a few changes to the codebase in order to clean up and merge shared devDependencies in the root package.json.

Changes

• Merged dependencies and devDependencies as dependencies in root package.json. Since this package is never installed, we can install all root packages as dependencies.
• Removes unused @babel/core and babel-loader dependencies from client.
• Upgraded next to 12.0.7 to support eslint@8 (support added in 12.0.5)
• Move all shared devDependencies (@types/node, eslint, prettier, etc.) to dependencies in the root package.json. This makes it a little more obvious which dependencies are shared across our packages, and which are used within only a single package.
• Created a root .prettierignore (prettier ignores nested ignore files).
• Added configuration for prettier to support *.sol

[vercel[bot]]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/devdaojobboard/dao-job-board/4aD9NrrPn1RVE8XY64nVrA1MJTz4
✅ Preview: https://dao-job-board-git-merge-root-dependencies-devdaojobboard.vercel.app