more human friendly output formating

[pinkavaj]

Align channel numbers and power values to be easily readable.

This substantially improves readability the %10.2f, can be even %12.2f to make high power values readable.

[rxseger]

👍 good fix, before:

kalibrate-hackrf $ src/kal -s EGSM -g 40 -a 1 -l 62 -g 40  -D -v
kal: Scanning for E-GSM-900 base stations.
E-GSM-900:
    chan: 22 (939.4MHz + 39.136kHz) power: 243518.71
    chan: 23 (939.6MHz + 13.909kHz) power: 321138.61
    chan: 24 (939.8MHz - 10.856kHz) power: 362856.59
    chan: 25 (940.0MHz - 35.487kHz) power: 347375.78
    chan: 26 (940.2MHz - 36.102kHz) power: 307431.81
    chan: 124 (959.8MHz - 17.677kHz)    power: 427226.27
    chan: 979 (926.0MHz - 18.516kHz)    power: 263179.21
    chan: 994 (929.0MHz + 7.512kHz) power: 765887.06
    chan: 995 (929.2MHz - 16.818kHz)    power: 603168.38
    chan: 996 (929.4MHz - 16.788kHz)    power: 607769.77

after:

kal: Scanning for E-GSM-900 base stations.
E-GSM-900:
    chan:   22 (939.4MHz + 39.334kHz)   power:  540322.74
    chan:   23 (939.6MHz + 14.615kHz)   power:  580987.76
    chan:   24 (939.8MHz + 14.825kHz)   power:  536549.80
    chan:  124 (959.8MHz - 17.738kHz)   power:  433407.70
    chan:  993 (928.8MHz + 32.391kHz)   power:  585843.51
    chan:  994 (929.0MHz + 7.420kHz)    power:  599199.81
    chan:  995 (929.2MHz - 17.577kHz)   power:  474478.79