Search support for TNFS servers

[trekawek]

I started working on the search support for the TNFS, based on the patterns. It's mostly implemented in the tnfsd, but some small changes in the firmware and config are required too.

The new feature is enabled by starting the filter with !, e.g.:

!decathlon

will find all files, regardless of their parent directories, starting with the decathlon name (case insensitive). However, we may think about some other convention for enabling this feature in the config app.

The code is quite fresh and needs more testing, that's why the PRs are in the draft mode for now:

#844
FujiNetWIFI/tnfsd#16
FujiNetWIFI/fujinet-config#109

[trekawek]

Feature has been finished and merged into tnfsd and fujinet-firmware.