[v2] Command handler unit tests require a lot of mocks

[t1m0thyj]

In a unit test that calls ICommandHandler.process and mocks an ImperativeConfig.instance.config object with the exists: true property defined, several mocks are required which may be an inconvenience for plug-in developers.

For an example, see this sample plug-in unit test: zowe/zowe-cli-sample-plugin@a6b6d22#diff-c5dfd517fddad71ab1fe78c762be9a365f981aa118a4b3a72427717d679d634c

The following functions require mocks to be defined on the ImperativeConfig instance:

• LoggerUtils.censorRawData - envVariablePrefix, config.api.layers.get, config.api.secure.secureFields
• ConfigAutoStore.findActiveProfile - loadedConfig.profiles

[zFernand0]

After a short discussion, we wanted to reduce code duplication.
This might be a good enhancement for the cli-test-utils package.
We could add a few clever ways to mock these methods 😋
(not a good first issue 😅 )