Avoid GraphQL type name collisions

[jorgebay]

Certain table names combinations could cause collisions in the generated names for types.

For example:

tables named: tbl_something and tbl_something_input will try to use the names TblSomethingInput for 2 different tasks.

We should make sure unique names are generated. We can do that by storing the names of the graphql types generated and add increments only if there is an existing type with the same name.

In the example above, it would be:

type TblSomethingInput {}
input TblSomethingInput2 {}