Add and use collection Capacity properties

[Washi1337]

Includes:

• Add RefList::Capacity.set
• Add IMetadataTableBuffer::EnsureCapacity(int)
• Changes some internal ModuleDefinition::GetXCollection methods to return ICollection<T> instead of IEnumerable<T>.
• Use of List.Capacity in various reader and builder methods when the number of elements to add is known.

[Washi1337]

Before (v4.11.0):

Method	Mean	Error	StdDev	Gen 0	Gen 1	Gen 2	Allocated
CoreLib_ReadWrite	981,262.94 μs	19,586.006 μs	18,320.763 μs	33000.0000	13000.0000	2000.0000	298,313 KB

After:

Method	Mean	Error	StdDev	Gen 0	Gen 1	Gen 2	Allocated
CoreLib_ReadWrite	959,691.30 μs	17,256.368 μs	21,192.370 μs	32000.0000	13000.0000	2000.0000	287,493 KB