binja: `get_instruction` should attach the list of associated LLIL instructions to the instruction object

At https://github.com/mandiant/capa/blob/688841fd3b337865c7affb39ac62c6454f9c4d94/capa/features/extractors/binja/extractor.py#L78

Currently, several instruction level analysis tries to get the associated LLIL instruction given an address using the API `get_llil_at` or `get_llils_at`. These should be avoided and the lookup should better be just done once

Start in capa/features/extractors/binja/extractor.py around line 78 and inspect how instruction objects are created. Trace the get_llil_at and get_llils_at call sites to understand the current repeated lookups. Done means the instruction object carries its associated LLIL instructions and instruction-level analysis no longer performs those lookups repeatedly.

Written by the indexing model from the issue text.