Improve CCM documentation

- Rephrase function/parameter/enum/define/error descriptions into full and
  clear sentences.
- Make sure to adhering to the Arm writing guidelines.
- Fix missing/incorrect Doxygen tags.
- Standardize terminology used within the file.
- Fix iv_len values per the standard.

GitHub PR: #1305
diff --git a/library/error.c b/library/error.c
index e39fb09..fdfa94a 100644
--- a/library/error.c
+++ b/library/error.c
@@ -642,7 +642,7 @@
 
 #if defined(MBEDTLS_CCM_C)
     if( use_ret == -(MBEDTLS_ERR_CCM_BAD_INPUT) )
-        mbedtls_snprintf( buf, buflen, "CCM - Bad input parameters to function" );
+        mbedtls_snprintf( buf, buflen, "CCM - Bad input parameters to the function" );
     if( use_ret == -(MBEDTLS_ERR_CCM_AUTH_FAILED) )
         mbedtls_snprintf( buf, buflen, "CCM - Authenticated decryption failed" );
     if( use_ret == -(MBEDTLS_ERR_CCM_HW_ACCEL_FAILED) )