Enabling noUncheckedIndexedAccess and noPropertyAccessFromIndexSignature for stricter checks

[barrymun]

• enabling noUncheckedIndexedAccess and noPropertyAccessFromIndexSignature in tsconfig.json for stricter checks
• handling cases which are now highlighted by the compiler as potentially problematic
• switching to tripe equals checks where appropriate (=== and !==)

bug fixes

• handle case where getStorageValue("sync") returns an empty object if the user is unauthenticated, for example, and use local settings values instead
• handle cases where brandsCount and brandsVersion can be null

[chris-mosley]

oh good this was something i was running into while working on it