Fix VS Code tests auto discovery

[guyp-descope]

Switched to use pytest in VS Code so tests auto discovery will work and tests can be run easily.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
__init__.py	5	0	100%
auth.py	300	10	96%	61, 372, 374, 465–466, 477, 509, 520, 549, 593
common.py	70	0	100%
descope_client.py	113	3	97%	55, 79, 313
exceptions.py	26	0	100%
mgmt.py	45	0	100%
authmethod
__init__.py	0	0	100%
enchantedlink.py	82	0	100%
magiclink.py	85	0	100%
oauth.py	29	0	100%
otp.py	91	0	100%
password.py	61	0	100%
saml.py	26	0	100%
totp.py	47	0	100%
webauthn.py	102	0	100%
management
access_key.py	27	0	100%
common.py	55	0	100%
group.py	16	0	100%
jwt.py	12	0	100%
permission.py	15	0	100%
role.py	16	0	100%
sso_settings.py	41	0	100%
tenant.py	23	0	100%
user.py	87	0	100%
TOTAL	1374	13	99%