speedup 'hf mf chk' (#901)

* add separate timeout for tag response to nr_ar
* measure response time and use it for response timeout
* don't drop field between keyblocks
* some reformatting
* some whitespace fixes
* fishing for microseconds in TransmitFor14443a()
* allow arbitrary number of keys in MifareChkKeys()
* and move progress printing to MifareChkKeys()

Co-authored-by: uzlonewolf <github_com@hacker-nin.com>