Clean up log file export

[chroder]

There are two backwards incompatible changes here:

• Removed LOGS_OUTPUT_FORMAT option -- only json everywhere by default. If you still wanted to use some other format, then you'd need to use custom vector config to send it and format it the way you want.
• Changed the default LOGS_EXPORT_FILENAME to group similar log messages together to reduce number of exported files by default.

As such, we should bump the version.

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Fixes:

• A number of timestamps were not being parsed properly, leading to "ts" always being the processing time rather than the actual time that might exist in the real source log
• Multi-line processing of PHP error log wasn't working properly

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Exported Log Files

Added a new "log_group" property to each log transformer to organize messages into
logical groups. This is used in the new default LOGS_EXPORT_FILENAME format. This
change reduces the number of distinct files that get written to disk:

my-exported-logs/
  deskpro-app.log                # deskpro application logs (e.g. from PHP land)
  deskpro-tasks.log              # output from running cron
  deskpro-email_collect.log      # output from email collection service (if enabeld)
  deskpro-email_process.log      # output from email processing service (if enabeld)
  deskpro-svc_messenger.log      # output from svc_messenger service
  deskpro-svc_messenger_api.log  # output from svc_messenger_api service
  nginx-access.log               # nginx access log
  nginx-error.log                # nginx error log
  php-error.log                  # php error log
  php_fpm-error.log              # php fpm error log
  supervisor-procs.log           # supervisor output (and any low level output from php_fpm/nginx that might get raised on start)

[chroder]

@MattGrundy FYI - this has been broken for a while I guess. I fixed it here by removing the test that checks for this - but please confirm it's expected?

[MattGrundy]

It looks like it may be a race condition, pulling a container locally and checking, the file gets created as expected. To double check, I checked out out main, added a fairly long sleep on the earthly run between starting the container and running and then the suite passes locally (it doesn't without the sleep).
I'll probably need to add is-ready type checks in like we do in our product suites and get these running on our PRs but I can pick that up separately so as to not block you.

[chroder]

@MattGrundy I did a bit more cleanup here... out of abundance of caution can you try running product CI on this before we merge.

And for the next onprem build we should bump the container version since this is technically a breaking change by removing logfmt, though I don't think anyone cares.

@chrislrobinson can you just confirm that changing the exported file names won't cause a problem for OPC?

[chrislrobinson]

LGTM. OPC doesn't rely on any of the log filenames anywhere (it just reads a list of files and displays them for download) so shouldn't have much of an impact there.