Capr Issue #99: Potential improvements to Capr

[guuswilmink]

This PR is linked to Issue #99.

Suggested functions:
isStandard.R: Given a path to CSV files with at least fields "sourceCode" and "conceptId", along with a database connection with a CDM and vocabulary schema, return a tibble of non-standard concepts. Allows for export of results for all concepts included (including standard). This function can help in quickly identifying non-standard concepts from tables of concept ids.

isStandardDB.R: Checks whether concepts that exist in a database are standard/non-standard and returns the non-standard concepts. The full table of standard and non-standard concepts can be saved as well. This is probably the most useful out of the 3 isStandard functions.

isStandardCS.R: Similar return as isStandard.R and isStandardDB, but performs the check given a Capr ConceptSet class object rather than CSV files. Does not capture source value (as these are not relevant for concept sets).

countOccurrences.R: Given a vector of concept IDs and a connection to a CDM instance, count the number of occurrences of: 1) persons with concept 'x'; 2) records with concept 'x'; 3) persons with concept 'x' or descendants of 'x'; 4) records with concept 'x' or descendants of 'x'
To demonstrate and further clarify this function I have attached a PDF with example usage. Is this already possible within Capr?

@mdlavallee92 I have incorporated your feedback provided in issue #99; please let me know if this is to your expectations.

[mdlavallee92]

thanks @guuswilmink can you please recreate this PR targeting the develop branch instead of the main branch. As part of the HADES procedure, any feature changes need to go to the develop branch first. Then we do a release on the main branch.