This moves the op sanitizer descriptions into Rust code and prepares for
eventual op import from `ext:core/ops`. We cannot import these ops from
`ext:core/ops` as the testing infrastructure ops are not always present.
Changes:
- Op descriptions live in `cli` code and are currently accessible via an
op for the older sanitizer code
- `phf` dep moved to workspace root so we can use it here
- `ops.op_XXX` changed to to `op_XXX` to prepare for op imports later
on.
2c621f5894