[SPIR-V] Validate and fix bit width of scalar registers (#95147)

This PR improves legalization process of SPIR-V instructions. Namely, it
introduces validation and fixing of bit width of scalar registers as a
part of pre-legalizer. A test case is added that demonstrates ability to
legalize instructions with non 8/16/32/64 bit width both with and
without vendor-specific SPIR-V extension
(SPV_INTEL_arbitrary_precision_integers). In the case of absence of the
extension, a generated SPIR-V code will fallback to 8/16/32/64 bit width
in OpTypeInt, but SPIR-V Backend still is able to legalize operations
with original integer sizes.