Added more input data types for pad (#2179)
* added more input data types for pad
* replacing the comments
* replacing the comments
* added first set of tests
* added tests
* added more tests
* keep NGRAPH test
* avoid type cast
* avoid type conversion for value float to T
* fixed tabs
* Update tests exclusion list
* Nits
* comments fix
* Format files
* Nit updates
* rebased