Add function to validate presence of all geographies in user-provided crosswalk file

[malcalakovalski]

Currently, the onus is on the metric lead to check whether all relevant geographies are present in the data which could be erroneous given all the different years and crosswalk files.

We will add a function to:

• Check for geography wherein user provides the crosswalk walk file path and function assesses whether all geoids match/are present.