Adds support for ArrayType in SparseConstantType

Adds the ability to have SparseConstantType utilize ArrayType as it's base_type

Moves application of inner_encoding of ArrayType to classmethod ArrayType._apply_inner_encoding

Updates test_sparse_constant_value_interop
Improves encoding and fill_value verification

Improves verification for value_encoding and fill_value

Adds inner_fill_value to ArrayType/Value

Updates tests
Fixes bugs in ArrayType, ConstantType and _cleanse_value
Merge pull request #82 from blazetopher/param_type_updates

Param type updates