[Core] Print INFO log from SDK

[jiasli]

Description
This PR requires microsoft/knack#221.

Previously when --verbose is specified, only cli.* loggers' INFO logs are printed. Now all azure.* loggers' INFO logs are printed, including the CLI loggers which are renamed to azure.cli.*.

Example:

> az group show -n fy --debug
...
DEBUG: azure.cli.core: Modules found from index for 'group': ['azure.cli.command_modules.resource']
DEBUG: azure.cli.core: Loading command modules:
DEBUG: azure.cli.core: Name                  Load Time    Groups  Commands
DEBUG: azure.cli.core: resource                  0.009        35       164
DEBUG: azure.cli.core: Total (1)                 0.009        35       164
...
INFO: azure.core.pipeline.policies.http_logging_policy: Request URL: 'https://management.azure.com/subscriptions/0b1f6471-1bf0-4dda-aec3-cb9272f09590/resourcegroups/fy?api-version=REDACTED'
INFO: azure.core.pipeline.policies.http_logging_policy: Request method: 'GET'
INFO: azure.core.pipeline.policies.http_logging_policy: Request headers:
INFO: azure.core.pipeline.policies.http_logging_policy:     'Accept': 'application/json'
INFO: azure.core.pipeline.policies.http_logging_policy:     'x-ms-client-request-id': 'd8fa889e-1822-11eb-b2f8-84a93e63aa78'

> az group show -n fy --verbose
...
INFO: azure.core.pipeline.policies.http_logging_policy: Request URL: 'https://management.azure.com/subscriptions/0b1f6471-1bf0-4dda-aec3-cb9272f09590/resourcegroups/fy?api-version=REDACTED'
INFO: azure.core.pipeline.policies.http_logging_policy: Request method: 'GET'
INFO: azure.core.pipeline.policies.http_logging_policy: Request headers:
INFO: azure.core.pipeline.policies.http_logging_policy:     'Accept': 'application/json'
INFO: azure.core.pipeline.policies.http_logging_policy:     'x-ms-client-request-id': 'd8fa889e-1822-11eb-b2f8-84a93e63aa78'

[yonzhan]

Core