Fix bug in ParseCRL_Extensions

[lealem47]

Description

• Fix a bug where the idx would get incremented where we don't expect it to be, in the else-if CRL_NUMBER_OID case in ParseCRL_Extensions()
• Store crl->crlNumber as a byte array to handle CRL numbers as long as 20 octets or 49 digits (https://datatracker.ietf.org/doc/html/rfc5280#section-5.2.3). This conversion unfortunately makes it so that crlNumber isn't stored when NO_BIG_INT is defined

Fixes #8574 and wolfSSL/wolfCLU#174

Also fixes zd#19611

Testing

Tested using wolfCLU with the CRL files provided in #8574 and wolfSSL/wolfCLU#174

Build wolfSSL with
./configure --enable-wolfclu --enable-crl

Then run wolfCLU with
./wolfssl crl -in crl_extention_test.pem -text

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[SparkiDev]

Using a mp_int is heavy weight for a 20 byte number - can allocate up to 1KB for storage of 20 bytes.
You can store the array of bytes and do a XMEMCMP and add a simple big-endian number larger comparison.

[lealem47]

Jenkins retest this please

[dgarske]

Looks good. Still on fence about backwards compatibility, but okay for now. Over to @SparkiDev

[dgarske]

Technically these have return codes... you might consider using mp_init_multi to simplify cleanup.

[dgarske]

Consider not calling free it alloc or init fails... Also the if(dec_num) below is optional since XFREE always does NULL check.