Allow tsql_validate_field_types to identify integer64

[dcolombara]

The tsql_validate_field_types() does not recognize integer64 class data

This a problem because it occurs when using fread to pull in large data. E.g., the following shows class integer64

csv <- fread("//dphcifs/APDE-CDIP/BRFSS/WA/2011-2023/WA_BRFSS_2011_2023_v3.csv")
class(csv$mracorg2)

This is what happens when running the function to validate the field types for upload to TSQL:

Error in tsql_validate_field_types(ph.data = csv, field_types = field_types) : 
  
🛑👿 The following R classes (column data types) are not recognized: integer64.
 These data types are not currently supported for TSQL conversion. If you think this is a mistake, please submit a GitHub issue.

[dcolombara]

ALSO, at the same time, FIX so that if R_type is integer it CAN have tsql_type varchar. That is not invalid. perhaps just flag with warning rather than isue == 'Incompatible types'
E.g., prevent this output:

Key: <colname>
    colname  R_type tsql_type is_valid              issue
1: cracasc1 integer   varchar    FALSE Incompatible types

[dcolombara]

Also, integers CAN be saved as floats. Should this really be invalid?

Key: <colname>
    colname  R_type tsql_type is_valid              issue
1: _packyrs integer     float    FALSE Incompatible types