wallet: add CheckDescriptorRangeBounds

Co-authored-by: w0xlt <woltx@protonmail.com>

ProcessUniValueDescriptor() checks for the descriptor range correctness, but since a
future commit adds an interface to import descriptors, those checks must be extracted
from RPC code. This commit adds a helper function to check ranges in descriptors and
checks for the range inside ImportDescriptor().
ProcessUniValueDescriptor keeps also the check as other RPC calls other than importdescriptors
also needs to check for ranges. This introduces a double check on the RPC path,
but the cost of it is minimal and can be accepted.