Repetitive Validation checks among Schemas and Accessors

Since WoodworkTableAccessor and Schema are separate objects and a Schema can be created independently of an Accessor, we have two sets of checks in each object that overlap some.

This will probably also be the case in the Series Accessor when that's created, as it will have validation checks of its own that will overlap with the Table Accessor and the column dictionary.

We can consider refactoring the validation in a way that doesn't re-validate unnecessary checks.