crypto/tls: expose names for CurveID and SignatureScheme #35499
Description
The constants for CurveID and SignatureScheme don't have any String() methods.
This makes printing these values (for example in log files) awkward as there is just a number.
To workaround this one can make a map to lookup from the constants to some friendly name (the constant name). As the constants already have custom types it would be best to implement the stringer interface for them in the standard library.
The idea is similiar to #30325
I created a first draft in #35297