Rewrite the driver in Rust; move the testbench tools out

The repository is now only the HPCS 6500 driver: a Rust library (serial
transport, every protocol command, block parsing, USBPcap captures, a
simulated instrument) and the hpcs6500 CLI with the flags of the former
hpcs6500.py, plus dump/capture for reverse engineering.

The lamp station, lamp export, TM-30, label printer and LED calibration
move to B4L/lamp-testbench. Golden tests pin the Rust output to the Python
driver's: parsed values bit-exact, report text, CSV and number formatting.
The Python driver is at tag python-final.

tests/golden/csv_r04.txt

@@ -0,0 +1,2 @@
+timestamp,Phi_lm,eta_lm_W,CCT_K,Duv,x,y,u,v,u_prime,v_prime,SDCM,Ra,R1,R2,R3,R4,R5,R6,R7,R8,R9,R10,R11,R12,R13,R14,R15,Phi_e_mW,Phi_euv_mW,Phi_eb_mW,Phi_ey_mW,Phi_er_mW,Phi_efr_mW,Phi_eir_mW,Phi_e_total,CIE_X,CIE_Y,CIE_Z,TLCI,PeakSignal,DarkSignal,Compensate,Voltage_V,Current_A,Power_W,Freq_Hz,PF
+T,479.8302917480469,57.09168243408203,5655.5185546875,0.005520321428775787,0.32882028818130493,0.3488074243068695,0.20148152112960815,0.3205926716327667,0.20148152112960815,0.4808890223503113,4.696867942810059,83.00994873046875,82.22040557861328,94.05892181396484,93.2469253540039,76.50690460205078,81.42030334472656,89.34086608886719,83.16636657714844,64.1189193725586,4.818240642547607,84.18575286865234,76.09269714355469,60.0699348449707,86.59054565429688,96.74826049804688,76.01618194580078,1491.9422607421875,0.0,469.8638610839844,679.650634765625,330.7580261230469,11.141565322875977,0.0,1491.4139404296875,662.2772216796875,702.5333251953125,649.290283203125,67.87500762939453,53051.0,2228.0,2834.0,230.30111694335938,0.06532319635152817,8.404557228088379,50.02182388305664,0.558664858341217