Add CalCat credentials to cal_tools

Description

As discussed @roscar, this changes cal_tools.mdc_config to a more generic cal_tools.restful_config to add CalCat credentials as well.

How Has This Been Tested?

Tested with new LPD notebook using calibration_client with credentials supplied via this MR.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Reviewers

@roscar @kluyvert