Improve beautify-timing-report.pl

[kittennbfive]

The current version is an early release to be improved. I released it as public domain so feel free to mess with the code!

The bit missing compared to the script from 2020 by Haakan T. Johansson is that the signal names are not shortened and no "blocks" are shown, as i am not sure how to proceed to make it "portable" between outputs from nextpnr for different FPGA architectures.

One simple idea is to remove everything from the end that is in uppercase including the _-character, but this will make a mess if they are signal-names in uppercase...

Another idea would be to include a list of blocks that can occur and remove them specifically, but making this list, especially for all currently supported architectures, is probably a pain.

Feel free to write down your ideas here...