Implement controls to adjust OpenOCD behavior during when it tries to detect which watch point was hit (riscv_hit_watchpoint)

[aap-sc]

This issue is a result of conversation during the code review here: #1056 (comment)

Suggestions proposed by @JanMatCodasip (that I support)

1. disable riscv_hit_watchpoint() by default 

EDITORIAL NOTE: or at least implement a control to disable it.

create a command that allows the user to enable this alternative watchpoint hit detection algorithm
- if OpenOCD detects that "hit" bits are not implemented by the target:
    - produce a warning to the user
    - print a hint to the user how to enable the alternative watchpoint hit detection
    - print a warning to the user that the alternative detection has limitations (as we discussed above: it is not 100% reliable, not all ISA extensions are supported, extra memory reads are performed, etc.)