Make the naming scheme for dispatched functions more consistent

Make the naming scheme for dispatched functions more consistent

The new naming scheme consistently usese the `OSSL_FUNC_` prefix for all
functions which are dispatched between the core and providers.

This change includes in particular all up- and downcalls, i.e., the
dispatched functions passed from core to provider and vice versa.

- OSSL_core_  -> OSSL_FUNC_core_
- OSSL_provider_ -> OSSL_FUNC_core_

For operations and their function dispatch tables, the following convention
is used:

  Type                 | Name (evp_generic_fetch(3))       |
  ---------------------|-----------------------------------|
  operation            | OSSL_OP_FOO                       |
  function id          | OSSL_FUNC_FOO_FUNCTION_NAME       |
  function "name"      | OSSL_FUNC_foo_function_name       |
  function typedef     | OSSL_FUNC_foo_function_name_fn    |
  function ptr getter  | OSSL_FUNC_foo_function_name       |

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12222)