t/jobs/t0034: add test for the log_issue_time option

t/jobs/t0034: add test for the log_issue_time option

Add a test to check the newly added option 'log_issue_time'. Generate
log files using the option and check that lines in the log files have
the format described in the "Log File Format" section in HOWTO.rst.

This test case has the logic same as t0033 except the log file names and
matching patterns. Factor out the logic to the new class
FioJobFileTest_LogFileFormat.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240829085826.999859-10-shinichiro.kawasaki@wdc.com
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>