Add multiple fixes for ffc key generation using invalid p,q,g parameters.

Add multiple fixes for ffc key generation using invalid p,q,g parameters.

Fixes #11864

- The dsa keygen assumed valid p, q, g values were being passed. If this is not correct then it is
  possible that dsa keygen can either hang or segfault.
  The fix was to do a partial validation of p, q, and g inside the keygen.
- Fixed a potential double free in the dsa keypair test in the case when in failed (It should never fail!).
  It freed internal object members without setting them to NULL.
- Changed the FFC key validation to accept 1024 bit keys in non fips mode.
- Added tests that use both the default provider & fips provider to test these cases.

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/12176)