The output of Display should not change in stable crates for types that
have well defined formatting and ones that implement FromStr.
Crates that are included in the mutation testing have been updated to
test all relevant Display implementations.
Remove the exclusion so that the Display implementations are included in
mutation testing.
cargo-mutants 25.0.1 introduced a new mutation pattern that deletes an
arm of a match statement or replaces a match guard with true and false.
These are applied in sections that have been excluded from mutation
testing and cause false positives.
The match patterns are also now stricter causing previously excluded
`impl` to be included.
Exclude the new match arm and guard mutation patterns.
Add `impl fmt::` versions for Debug and Display.
Jamil Lambert, PhD
Shing Him Ng