Instrumentation: Compress consecutive Z_() calls for speed

[t-b]

As can be seen at e.g.

https://github.com/byte-physics/igor-unit-testing-framework/blob/25fb93dcf86b1d95e53582a47d52ec2cb0599645/tests/test-tracing_instrumented.ipf#L20-L23

we currently output multiple Z_() calls in a row. I would be nice if we could compress these cases to just one Z_() call. The advantage would be speed.

[Garados007]

Ideas for speedup (they have to be tested)

• collapse consecutive Z_ calls to one line
• order Z_ calls
• remove optional parameter for consecutive lines and make it mandatory
• Remove for loop in Z_ and make it one statement
• special case for log lines=1

We need benchmarks for this

[t-b]

Look also into compressing multiple Z_ calls multiline comments.