argumentParsers: precompile argument and string maps

[NDStrahilevitz]

The Fix

Many String() and Parse functions had inner constant helper maps.
These maps were reallocated on each call, which could overtime cause signifacnt GC overhead.
This fix initializes the maps before the functions, making sure they are reused and not repeatedly reallocated.

Performance analysis

This fix was found while benchmarking tracee with a specific workload - a script running strace ps -ef repeatedly.

Running pprof on this case gave the following flame graph:

Note the runtime.mapassign_fast64 that is a significant repeating code path.

With this fix we get this flame graph:

Simply preallocating the map one time on the module init avoids the constant repeating calls to runtime.mapassign_fast64 while constructing the map on each function call.

Of course, this workload brought out this function on the extreme due to it being relevant to the workload running in a loop, however it isn't impossible that these helpers would cause overhead overtime for different type of workloads (There are many more maps there were optimized in this PR).

This is a quick and easy change which is similar in nature to precompiling a regex.

[rafaeldtinoco]

LGTM AND it is a nice change indeed. I'm fixing the git log (to wrap at correct column). Thanks!