LP#1710949: add tests for blocking after failed attempts

LP#1710949: add tests for blocking after failed attempts

Enhance the live tests to verify that attempts to log in
get blocked after too many failed ones; this assumes
a stock value for block_count.

General testing plan:

[1] Use srfsh to test, e.g.,

srfsh# request open-ils.auth open-ils.auth.login {"identifier":"99999389406","password":"12345","type":"opac","org":1}

[2] Try various scenarios:

    - wrong password
    - type = staff but user doesn't have STAFF_LOGIN
    - repeated failed attempts
    - barcode is inactive
    - using "identifier" in conjunction with opac.barcode_regex set
    - using "username" or "barcode"
    - supplying a workstation name that exists
    - ... or does not
    - user is inactive
    - user is marked barrred

Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>