Allow integer for cohortId

[anthonysena]

Allows for the specification of a cohort definition set & negative control outcome definition set with an integer value for the cohortId column.

Additional changes included in this PR:

• Removal of the inst/csv/cohortDefinitionSetSpecificationDescription.csv and inst/csv/negativeControlOutcomeCohortSetSpecificationDescription.csv files. These are simply created using the createEmpty*DefinitionSet functions. Data types are handled in the functions where appropriate.
• Adds internal function assertLargeInteger to check that a cohortId or outcomeConceptId are integer values. Using a function like checkmate::assertIntegerish did not work in the case where a cohortId is a numeric/double with a zero mantissa.
• Adds test cases to ensure that integer value is allowed for the cohortId column and the assertion of large integers works as intended.