Rename all getters to use get/get0 in name

For functions that exist in 1.1.1 provide a simple aliases via #define.

Fixes #15236

Functions with OSSL_DECODER_, OSSL_ENCODER_, OSSL_STORE_LOADER_,
EVP_KEYEXCH_, EVP_KEM_, EVP_ASYM_CIPHER_, EVP_SIGNATURE_,
EVP_KEYMGMT_, EVP_RAND_, EVP_MAC_, EVP_KDF_, EVP_PKEY_,
EVP_MD_, and EVP_CIPHER_ prefixes are renamed.

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15405)
diff --git a/demos/digest/EVP_MD_stdin.c b/demos/digest/EVP_MD_stdin.c
index 3e24f34..71a3d32 100755
--- a/demos/digest/EVP_MD_stdin.c
+++ b/demos/digest/EVP_MD_stdin.c
@@ -63,9 +63,9 @@
         return 0;
     }
     /* Determine the length of the fetched digest type */
-    digest_length = EVP_MD_size(message_digest);
+    digest_length = EVP_MD_get_size(message_digest);
     if (digest_length <= 0) {
-        fprintf(stderr, "EVP_MD_size returned invalid size.\n");
+        fprintf(stderr, "EVP_MD_get_size returned invalid size.\n");
         goto cleanup;
     }