Supporting custom granularity in time_spine

[pgoslatara]

Resolves #

Problem

Solution

Checklist

• I have run this code in development, and it appears to resolve the stated issue.
• This PR includes tests, or tests are not required or relevant for this PR.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
src/dbt_bouncer
config_file_validator.py	64	2	97%	87, 93
parsers.py	158	8	95%	207, 394, 396, 402, 477, 534, 536, 539
runner.py	76	4	95%	134, 170–171, 232
utils.py	101	19	81%	42, 47, 136–154, 177
src/dbt_bouncer/checks/manifest
check_models.py	200	1	99%	542
check_unit_tests.py	47	3	94%	107, 158, 210
src/dbt_bouncer/checks/run_results
check_run_results.py	22	2	91%	97–98
TOTAL	3869	39	99%

Tests	Skipped	Failures	Errors	Time
1	0 💤	0 ❌	0 🔥	12.015s ⏱️