SMTChecker support for `blobbasefee`

[nikola-matic]

Given the recent introduction of blobbasefee in #14755 for the Cancun fork, blobbasefee support should be implemented for the SMT checker as well. See implementation of basefee (London) for reference: #11785

[nikola-matic]

@pgebal may be of interest to you. If I have some spare time, I may also look into this.