Provide high-level api for key management functions (create, add, edit, import, export, etc) that use underlying gpgme[pp] functions.
API should simplify and abstract high-level functionality instead of providing 1:1 parity with underlying gpgme functions. For example, nodejs `gpgKeyExport(...)` would be the only function for importing keys could use multiple underlying gpgme[pp] functions:
```
gpgme_error_t gpgme_op_import (gpgme_ctx_t ctx, gpgme_data_t keydata) file/stdin ASCII or binary
gpgme_error_t gpgme_op_import_keys (gpgme_ctx_t ctx, gpgme_key_t *keys) in-memory
gpgme_op_receive_keys (gpgme_ctx_t ctx, const char *keyids[]) keyserver or external source
```