remove trigger logic at the edges, increase offset in global eta/phi strips

This MR simplifies the logic by

• removing the special treatment of hits at global eta/phi borders (i.e. we now really run our logic directly on the central 512 bins in global eta and phi, relying on the left and right offsets to avoid border effects)
• increasing the size of the left and right offset (i.e. 32+512+32 bits, as opposed to 20+512+20) to match half of the size of the window (64 bits) used to search for the first candidate in an "etasplit" (find_first_nonzero)

Synthesis takes 1h35', implementation takes 2h03'.