feat(filter): no longer infer scope in filters (#8137)
### Description
Previously we would infer scope for name filters if there was exactly
one matching package.
e.g. `turbo build --filter=ui` would run `@a/ui#build` if there was a
`@a/ui` package in the workspace
This is confusing and can result in accidentally breaking filters when a
conflicting package is added e.g. adding `@b/ui` would cause *no* tasks
to be run along with a zero exit code.
### Testing Instructions
Updated unit test to verify inference no longer works and using the
explicit package name still works.
