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_r03.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,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0