Support concat for DLT traces

[MortronMeymo]

Currently when trying to open multiple DLT traces via concat they are opened as text files and not as DLT files. Since some tools automatically split traces into smaller files (since said tools are too slow with large files) it would really help to have this feature.

[vladirupanov]

I can only second the mentioned enhancement. we also suffer from files being cut into 100MB-chunks, and it is not very meaningful to reapply the same filters N times to analyse a run. Unfortunately the cut files are sometimes .pcapng.

I think it is a low hanging fruit, independent from the rest, and it would improve the way people interact with the tool and get more users among the ones analyzing tickets.

[DmitryAstafyev]

Concat introduced for DLT with chipmunk 3