This upgrade came with a number of new lints that needed to be fixed across the code base. Primarily: explicit return types on functions, and explicit visibility modifiers on class members.
by fixing the cause rather than the symptom: this upgrades the code to use the new, recommended JSX transform mode of React 17+, which no longer requires you to import React manually just to write JSX.
This is an Element project (in the vector-im repo) so the Copyright
should be for New Vector: it was incorrectly attributed to the
foundation for some files (and some files were missing headers).
