feat: create local storage abstraction

[KevinWu098]

Summary

1. Create localStorage abstractions for getting, setting, and removing. Not all getters/setters/removers are utilized, but I've chosen to keep/include them for completeness-sake.

Test Plan

1. Confirm that every abstraction works as intended
2. Or, assuming that the abstractions are all written correctly, you can read over the PR and confirm that they were abstracted one-to-one

Issues

Closes #889