Disambiguate physical units from declared variables

[clinssen]

Fixes #1260.
Fixes #1010.

[github-actions]

Bencher Report

Branch	1295/merge
Testbed	ubuntu-latest

🚨 1 Alert

Iteration	Benchmark	Measure Units	View	Benchmark Result (Result Δ%)	Upper Boundary (Limit %)
0	tests/nest_continuous_benchmarking/test_nest_continuous_benchmarking.py::TestNESTContinuousBenchmarking::test_stdp_nn_synapse	Latency seconds (s)	📈 plot 🚷 threshold 🚨 alert (🔔)	3.95 s (+16.30%) Baseline: 3.40 s	3.74 s (105.73%)

Click to view all benchmark results

Benchmark	Latency	Benchmark Result seconds (s) (Result Δ%)	Upper Boundary seconds (s) (Limit %)
tests/nest_continuous_benchmarking/test_nest_continuous_benchmarking.py::TestNESTContinuousBenchmarking::test_stdp_nn_synapse	📈 view plot 🚷 view threshold 🚨 view alert (🔔)	3.95 s (+16.30%) Baseline: 3.40 s	3.74 s (105.73%)

Benchmark	Latency	Benchmark Result seconds (s) (Result Δ%)	Upper Boundary seconds (s) (Limit %)
tests/nest_continuous_benchmarking/test_nest_continuous_benchmarking.py::TestNESTContinuousBenchmarking::test_stdp_nn_synapse	📈 view plot 🚷 view threshold 🚨 view alert (🔔)	3.26 s (-3.76%) Baseline: 3.39 s	3.73 s (87.49%)

Benchmark	Latency	Benchmark Result seconds (s) (Result Δ%)	Upper Boundary seconds (s) (Limit %)
tests/nest_continuous_benchmarking/test_nest_continuous_benchmarking.py::TestNESTContinuousBenchmarking::test_stdp_nn_synapse	📈 view plot 🚷 view threshold 🚨 view alert (🔔)	3.24 s (-4.33%) Baseline: 3.39 s	3.73 s (86.97%)

🐰 View full continuous benchmarking report in Bencher

[pnbabu]

Should we forbid this altogether? Users shouldn't be able to create variables with names that match unit types, right?

[clinssen]

This is not tenable as many units use letter that will be commonly used as parameter names, like a, b, c, d. Hence the "if it's not defined as a variable, it's a unit" rule.

[pnbabu]

What happens when V = 1 V?