Misc. docs and renames for niche ECS internals

[JaySpruce]

Objective

Some structs and methods in the ECS internals have names that don't describe their purpose very well, and sometimes don't have docs either.

Also, the function remove_bundle_from_archetype is a counterpart to BundleInfo::add_bundle_to_archetype, but isn't a method and is in a different file.

Solution

• Renamed the following structs and added docs:

Before	After
AddBundle	ArchetypeAfterBundleInsert
InsertBundleResult	ArchetypeMoveType

• Renamed the following methods:

Before	After
Edges::get_add_bundle	Edges::get_archetype_after_bundle_insert
Edges::insert_add_bundle	Edges::cache_archetype_after_bundle_insert
Edges::get_remove_bundle	Edges::get_archetype_after_bundle_remove
Edges::insert_remove_bundle	Edges::cache_archetype_after_bundle_remove
Edges::get_take_bundle	Edges::get_archetype_after_bundle_take
Edges::insert_take_bundle	Edges::cache_archetype_after_bundle_take

• Moved remove_bundle_from_archetype from world/entity_ref.rs to BundleInfo. I left the function in entity_ref in the first commit for comparison, look there for the diff of comments and whatnot.
• Tidied up docs:
  • General grammar and spacing.
  • Made the usage of "insert" and "add" more consistent.
  • Removed references to information that isn't there.
• Renamed BundleInfo::add_bundle_to_archetype to BundleInfo::insert_bundle_into_archetype for consistency.

[alice-i-cecile]

Really nice set of changes. AddBundle in particular has really confused and aggravated me in the past. I agree with all of these changes, and while the type names are verbose, they're both arcane and internal so I think it's a fine tradeoff.

[hymm]

changes make sense to me.

[hymm]

nit: it might be better to name this and other methods ArchetypeAfterInsertBundle and *_insert_bundle() to match the insert_bundle ordering.

[JaySpruce]

I went back and forth on this, but I stuck with bundle_insert because I thought insert_bundle might sound too much like an "action", like get_archetype_after_insert_bundle would actually be doing the insert itself. Not married to it though

[hymm]

I don't really have too strong feelings here either and I don't think it's worth thinking about too hard. The new names are better, so lets just ship it.