Speedup in searching TRegister entries

[undroidwish]

Howdy epsilonrt,

please find attached a patch for a hash based approach in order to map Modbus addresses to a TRegister
struct. In my specific case with 96 holding regs, 96 input regs, 96 coils, 96 discrete inputs I observed a
speedup of factor 5 in my main loop. I believe this is worth the expense of 28 extra RAM bytes in a
Modbus object.

BR,
Christian

modbus.txt

[epsilonrt]

Hi Christian,
I thank you for this work.
I will have to examine your code in detail as soon as I am available.
You would need to create a pull-request so that I can integrate it into the repository : https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request
Regards