Convert dates from `yyyy-mm-dd` format into 20APR2019 format `Datetime` format removes the time and outputs date in the same way Able to handle truncated dates as well (e.g. just the year or year and month)

`dplyr::case_when()` will check all RHS expressions on the input, this means if these expressions return warnings, they will happen even then the input doesn't doesn't satisfy the LHS. For this reason, I had to 'quiet' all `lubridate` functions. This `format_date()` function was tested with the inputs in the examples, all gave the expected returned value, so there should be no issues.