Filter paths before parsing and lowering AST when possible

[izcoser]

Filter paths before parsing and lowering AST when possible

[0xalpharush]

We don't currently filter out beforehand because a file that is filtered out may be referenced by other files e.g. library/parent contract in inheritance that must also be analyzed. In terms of performance, I would expect a higher priority is reducing the time we spend in solc (foundry-rs/foundry#7212). We do need to revisit Slither's performance though and I'm sure there's a way to more intelligently filter to eliminate this overhead.

related issue #2026

[izcoser]

Targeting a specific contract like src/ContractX.sol will skip analyzing others, so one would expect --filter-paths to behave similarly. Thank you for clarifying.