We currently have multiple flags for targeting which functions to compile, but
they are actually mutually exclusive. This PR consolidates to a single
`compilationMode: 'annotation' | 'infer' | 'all'` flag:
* Annotation compiles only functions that explicitly opt-in with "use forget"
* Infer compiles explicitly opted-in functions (via "use forget") as well as any
known/inferred components or hooks:
* Component declarations
* Component or hook-like functions (same rules as the ESLint plugin but with an
extra check for whether it uses JSX or calls a hook)
* All compiles all top-level functions. We should get rid of this in a follow-up
and make tests use infer mode by default, and add explicit opt-ins where
necessary.
In all modes, "use no forget" always takes precedence and can be used to
opt-out. The default mode is now "infer".
Sorry about the thrash in advance! This removes the top level `forget` directory
which adds unnecessary nesting to our repo
Hopefully everything still works
