Pr05 Typescript Migration #18: Migrate client/modules/About & client/modules/Legal

[clairep94]

Picking off easy wins in the client/modules folder

• Was trying to record demos to show the steps to migrate a non-complex file for the Open Forum and did these
• Manually tested that all pages work after (as part of demos):

CHECKING.LEGAL.MIGRATION.mov

Changes:

• Migrate client/modules/About
• Migrate client/modules/Legal

Notes:

Cherry-picked relevant commits from the giant rough-work PR here for easier review

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines

[clairep94]

@raclim @khanniie Small easy one!