[HLSL] Refactor `DXILABI.h` to not depend on `ScopedPrinter.h`

[joaosaffran]

DXILABI.h currently depends on ScopedPrinter.h, which is quite heavy. Since DXILABI.h is included in multiple places, this dependency has increased clang compilation time by 2%. See https://llvm-compile-time-tracker.com/compare_clang.php?from=ca9ddd54b77020322a94a8032276b46cc1046522&to=d56fa965243bcdc115b8f262ce79cf2547500c6d&stat=instructions%3Au&sortBy=interestingness.

Requested from: #152229 (comment)