More clearly flag internal crates as such (#10963)

* More clearly flag internal crates as such

This commit is an attempt to more clearly flag internal crates in this
project as internal and not int

More clearly flag internal crates as such (#10963)

* More clearly flag internal crates as such

This commit is an attempt to more clearly flag internal crates in this
project as internal and not intended for external use. Specifically:

* Many crates are renamed from `wasmtime-foo` to
`wasmtime-internal-foo`.
* All of these crates now have `INTERNAL: ...` in their crates.io
description.
* All of these crates now have a warning at the top of their
documentation discouraging use.

This change is a result of rustsec/advisory-db#1999 where the goal is to
be crystal clear from a project perspective that usage of these crates
are highly discouraged and not supported. We'll still probably get such
advisories but we won't be considering them CVEs from the project itself
due to the internal nature of these crates and the discouraging
warnings.

Some concrete changes used here are:

* Inter-crate dependencies still use `wasmtime_foo` for naming and do
so with Cargo's package-renaming features.
* Crate renames are specified at the workspace level so the rename is
only in one locations and all other inherit it.
* Contribution documentation now has some brief guidelines about crate
organization.

* Update vet config

* Update checks for wasmtime-fiber

prtest:full

* Update publish script

* Another fiber rename

* Fix some doc tests

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