refactor: minimize pointers

[aleksasiriski]

Idea:
Avoiding to use pointers results in having less garbage collection (most vars are on stack) and makes the code more predictable (if something changes, it must be returned). Of course, not everything should be passed by value and not every pointer is heap allocated so some meaningful situations remain where a pointer is being used (relay, colly, retrievedResult).

Tips:

• avoid returning pointers, they will be heap allocated
• passing pointers down (func1->func2->func3, w/o returning them) is stack allocated
• passing pointers leads to possible changes in the data, whereas copy-by-value assures no changes in the func that passed it
• most structs are small and the big parts in them are usually pointers and not actual big data structs, so for most usecases passing copy-by-value vs pointer's performance penalty is negligible

Changes:

• Refactored colly to use less pointers, moving &params into returns
• Moved context to be the first param in functions (except if a structs is passed because it gets used/modified, than that is the first param)
• Made errors not be set via single retError pointer but returned and aggregated into an error slice
• Refactor cli flags, cache, config, search and bucket to avoid pointers
• Refactor rank and result to have better file structure and avoid pointers
• Refactor engines to have init collector func setup both col and pagesCol collector
• Refactor every file that uses config struct to accept only needed lesser structs as params

Off topic changes:

• Switch go.mod to require go1.22 and switched for range loops to use _, var syntax since it doesn't retain the same adress anymore

[k4lizen]

LGTM
GJ