[analyzer][z3] Use more elaborate Z3 variable names

Previously, it was a tedious task to comprehend Z3 dumps.
We will use the same name prefix just as we use in the corresponding dump method

For all `SymbolData` values:
    `$###` -> `conj_$###`
    `$###` -> `derived_$###`
    `$###` -> `extent_$###`
    `$###` -> `meta_$###`
    `$###` -> `reg_$###`

Reviewed By: xazax.hun,mikhail.ramalho

Differential Revision: https://reviews.llvm.org/D86223