sentSpawn functionality

[deltamolfar]

(Re-PR because I accidentally deleted previous fork)
Added :GetBool(), and review changes.

• Finally a way for E2 to spawn sents.
• For QoL, limited to wire/native gmod sents + entity tab entities, if wire_expression2_propcore_whitelist <= 0)
• Thirdparty addons support (ability to add/remove ents to be able to be spawned within whitelist + a hook with same logic as Expression2_CanEffect
• Entity registration is straightforward, and the sentSpawn does all the E2 to Lua castings itself (No need to put every check in _preFactory'ies).
• Ability to spawn ALL wire entities (if I didn't forget any).
• Few helper functions to sentSpawn.

While most of registration code/logic is from starfall prop_sent.lua, I've found and fixed ~10 sents + added ~6 that weren't originally there.

Current minor bugs:

• gmod_wire_dynamic_button doesn't spawn correctly (commented out).
• gmod_cameraprop and gmod_emitter spawn with no issue, but don't work as expected (commented out).
• Undo for some reason doesn't return E2 sent (classname), but e2_spawned_sent when user cancels sent.

[thegrb93]

Looks fine, might do a diff against starfall's to sanity check.

[thegrb93]

I think sents_default_params.lua needs to be put somewhere outside of lua/entities. putting lua files there registers the filename as an entity class.

[thegrb93]

Diffed the changes and they mostly look ok. The gmod_wire_value code is pretty messy, but whatever.

[deltamolfar]

• Alright, I've moved it and renamed sents_default_params.lua out of entities folder, to lua/wire/server/sents_registry.lua.
• Changed a whitelist/registry logic a bit (reinforced the registry reusability by thirdparty addons, by separating registering wire elements, and blacklisting).
• Few QoL fixes.

Regarding gmod_wire_value code is messy because I didn't like how it was implemented in sf, so I've decided to expand the value setting logic, while leaving support for the sf way. Code is messy, but I'm not sure how to make it cleaner without separating logic into few, never reused functions out of gmod_wire_value's preFactory. I think it's fine to leave it as is for now, as it will not really harm any future work, and maybe someday someone, or me, will refactor that.