This commit applies the Black format to the `dcorch/db`
files to ensure that it adheres to the Black code style guidelines.
Test Plan:
PASS: Success in stx-distcloud-tox-black
Story: 2011149
Task: 50445
Change-Id: I2560e5947fd1561e6b97b31dc2e735690813b340
Signed-off-by: Hugo Brito <hugo.brito@windriver.com>
51bee5a605