Create a dateless helper for logs with date-less timestamps

[rick-slin]

Describe the problem:

Some log files do not have the date in their timestamp. This is the case for ps.txt log files in MacOS/iOS for example. I wish to create a dateless_helper modeled on the yearless helper.

[joachimmetz]

@rick-slin given several short-comings in https://github.com/log2timeline/plaso/pull/4699 working on an alternative

• [x] ~~changed year less log helper to date less log helper - https://github.com/log2timeline/plaso/pull/4851~~
• [x] ~~change dtDateTime to support delta date - https://github.com/log2timeline/dfdatetime/pull/280~~
• [x] ~~change timeliner to handle a full date instead of just year - https://github.com/log2timeline/plaso/pull/4854~~
• [ ] change date less helper interface to be used by ps.txt log file parser
  • ~~_SetEstimatedDate to estimate the date based on the file entry, will set the granularity to no-date - https://github.com/log2timeline/plaso/pull/4859~~
  • _UpdateDate to update the date based on the time observed in the log format

[joachimmetz]

@rick-slin let me know when you have a draft PR for the ps.txt log parser, this will help finalize adding _UpdateDate to the date less helper interface

[rick-slin]

I should have time later this week.

[joachimmetz]

@rick-slin thanks no hurry, mostly a heads up that most of the "plumbing" should be there now

[rick-slin]

@joachimmetz I've created a draft for the ps.txt parser. It includes two different uses of the DateLessLogFormatHelper. See #4861

[joachimmetz]

@rick-slin thanks, I'll try to take a look over the weekend.

[joachimmetz]

Interesting format, so what are the cases here (STARTED TIME):

• 23Feb22 192:14.05 (date)
• Fri11AM 0:00.37 (date-less, relative day)
• 9:14AM 0:00.09 (date-less, today)