Repository Modernization Plan - Phase 2B: Remove redundant Algorithm() from Opts interfaces

[Soumya8898]

Remove redundant Algorithm() from Opts interfaces

Fixes #63

What

Removes the Algorithm() string method from KeyGenOpts, KeyDerivOpts, and KeyImportOpts interfaces, along with all 11 boilerplate implementations across opts structs.

Why

Every single implementation returned the hardcoded constant "IDEMIX". In a single-algorithm repository, algorithm dispatch via string identifiers is unnecessary overhead. The only two call sites were error messages in impl.go, which now use reflect.TypeOf(opts) for equivalent (and more informative) context.

Changes

File	Change
bccsp/types/crypto.go	Remove Algorithm() string from KeyGenOpts, KeyDerivOpts, KeyImportOpts
bccsp/types/idemixopts.go	Remove IDEMIX constant + 11 Algorithm() method implementations
bccsp/impl.go	Replace opts.Algorithm() with reflect.TypeOf(opts) in 2 error messages

Interfaces after this change

type KeyGenOpts interface {
    Ephemeral() bool
}
type KeyDerivOpts interface {
    Ephemeral() bool
}
type KeyImportOpts interface {
    Ephemeral() bool
}

[adecaro]

LGTM