Unify output formats

[dbeatty10]

As a follow-up to #2, make all 3 of the pre-existing format options available when using --dbt.

Usage

Usage for --dbt mode:

Default

$ data-diff --dbt

Found 1 successful model runs from the last dbt command.
- 1, black
+ 1, orange

JSON

$ data-diff --dbt --json 

Found 1 successful model runs from the last dbt command.
["-", ["1", "black"]]
["+", ["1", "orange"]]

Stats

$ data-diff --dbt --stats

Found 1 successful model runs from the last dbt command.
2 rows in table A
2 rows in table B
0 rows exclusive to table A (not present in B)
0 rows exclusive to table B (not present in A)
1 rows updated
1 rows unchanged
50.00% difference score

Extra-Info:
  diff_counts = {'id_a': 0, 'color_a': 0}
  exclusive_count = 0
  table1_count = 2
  table2_count = 2
  validated_unique_keys = [['id'], ['id']]