[CI][DEBUGGING] DMX dump not working for MC br switching + more than 9 transport channels

The dumping of the encoder-side dmx signal does not work for MC bitrate switching and MCT where more than 9 transport channels are present.

For bitrate switching, I assume that the varying number of transport channels is the problem. One could try to limit the dump to the minimum number of transport channels (which is 1 or 2 in McMASA - tagging @pihlajakuja and @vasilache), but that does not seem too helpful and also needs to be limited to br switching cases only. Alternatively, one could always output the maximum number (12 - MCT) and write zeros for the non-existing ones (don't know how difficult that would be). Finally, one could simply excluded br switching cases from the manual job where the dmx dump is being compared. Reproduce with:

IVAS_cod_flt_ref_debugging -mc 7_1_4 scripts/switchPaths/sw_mctech_5fr.bin 48 scripts/testv/stv714MC48c.wav bit

For the >9 tc case (MCT), this is how the res folder looks like:

ivas_input_dmx.id1.pcm
ivas_input_dmx.id2.pcm
ivas_input_dmx.id3.pcm
ivas_input_dmx.id4.pcm
ivas_input_dmx.id5.pcm
ivas_input_dmx.id6.pcm
ivas_input_dmx.id7.pcm
ivas_input_dmx.id8.pcm
ivas_input_dmx.id9.pcm
ivas_input_dmx.id:.pcm

This can be fixed by not incrementing a char, but using string formatting for the filename.