Increase and enhance fuzzy testing

[Xiaohanjlll]

Code coverage has been improved as follows:

libspdm_req_negotiate_algorithms.c          81.8% -> 95.3%       
libspdm_req_get_capabilities.c              75.5% -> 94.3%          
libspdm_rsp_capabilities.c                  91.6% -> 95.4%        
libspdm_rsp_algorithms.c                    61.6% -> 74.7%     
libspdm_rsp_certificate.c                   80.6% -> 82.5%
libspdm_rsp_challenge_auth.c                81.0% -> 84.1%
libspdm_rsp_csr.c                           64.6% -> 71.2%
libspdm_rsp_digests.c                       69.6% -> 77.3%
libspdm_rsp_finish.c                        76.9% -> 81.1%
libspdm_rsp_psk_finish.c                    74.2% -> 80.9%
libspdm_rsp_set_certificate.c               60.6% -> 67.4%
libspdm_rsp_measurements.c                  75.2% -> 78.4%
libspdm_req_psk_exchange.c                  76.6% -> 79.6%	
libspdm_rsp_key_exchange.c	            77.2% -> 80.8%
libspdm_rsp_version.c                       83.3% -> 86.7%

[jyao1]

Please describe clearly, what is enhanced.

[Xiaohanjlll]

Please describe clearly, what is enhanced.

I made some modifications to the existing test cases to make it easier for them to enter the subsequent branches.

[Do some customized settings to cover more code logical branch](https://github.com/DMTF/libspdm/pull/2623/commits/e239ae67c58caadfeb9e88f2f247c24c963b97dc)