add boolean and boolean metrics

[suelai]

What

Describe what the change is solving
It helps to add screenshots if it affects the frontend.

Get counts of TRUE and FALSE for boolean values. Right now the column type are text and numeric only
change the macros that detect the column types for BigQuery to recognise booleans and add two metrics of count_true and count_false

How

Describe the solution

Add an if condition to bigquery__get_column_type to include the boolean column type. Add two metrics of count_trueandcount_false`

relates to re-data/re-data#405

[davidzajac1]

@suelai thanks for all the contributions! Made a small change on this one to make it work for all the other adapters.

[suelai]

@suelai thanks for all the contributions! Made a small change on this one to make it work for all the other adapters.

Awesome, thank you!