tests: do not generate custom build for rng test

As a follow up to e15b34f, we modify the rng failure test so that it
does not generate a new build. To achieve this we do the following:

* Modify compontents and rules to not generate a cusom build.
* Remove the custom test_rng_fail config.
* Do not link the rng failure test against notrandombytes.c and instead
  implement our own randombytes.
* Updated test function names to use standard crypto_sign_* API
  instead of mld_* aliases as the mld_* namespace is no longer available
  as we are now using the default build with
  MLD_DEFAULT_NAMESPACE_PREFIX. Those functions which are not exposed
  in this way by default are wrapped with MLD_API_NAMESPACE.

Signed-off-by: Andreas Hatziiliou <andreas.hatziiliou@savoirfairelinux.com>

Author: L-series

BIBLIOGRAPHY.md

@@ -53,7 +53,6 @@ source code and documentation.
   - [test/configs/no_asm_config.h](test/configs/no_asm_config.h)
   - [test/configs/serial_fips202_config.h](test/configs/serial_fips202_config.h)
   - [test/configs/test_alloc_config.h](test/configs/test_alloc_config.h)
-  - [test/configs/test_rng_fail_config.h](test/configs/test_rng_fail_config.h)
 
 ### `FIPS202`
 
@@ -108,7 +107,6 @@ source code and documentation.
   - [test/configs/no_asm_config.h](test/configs/no_asm_config.h)
   - [test/configs/serial_fips202_config.h](test/configs/serial_fips202_config.h)
   - [test/configs/test_alloc_config.h](test/configs/test_alloc_config.h)
-  - [test/configs/test_rng_fail_config.h](test/configs/test_rng_fail_config.h)
 
 ### `HYBRID`
 

test/configs/configs.yml

@@ -427,18 +427,3 @@ configs:
       MLD_CONFIG_FILE:
         comment: "/* No need to set this -- we _are_ already in a custom config */"
 
-  - path: test/configs/test_rng_fail_config.h
-    description: "Using custom randombytes that can fail at specific invocation"
-    defines:
-      MLD_CONFIG_NAMESPACE_PREFIX: mld
-      MLD_CONFIG_CUSTOM_RANDOMBYTES:
-        content: |
-          #define MLD_CONFIG_CUSTOM_RANDOMBYTES
-          #if !defined(__ASSEMBLER__)
-          #include <stddef.h>
-          #include <stdint.h>
-          #include "src/sys.h"
-          int mld_randombytes(uint8_t *out, size_t outlen);
-          #endif
-      MLD_CONFIG_FILE:
-        comment: "/* No need to set this -- we _are_ already in a custom config */"