Multiple CC Authorizer support CCManager

[yhwen]

Fixes # .

Description

CCManager support multiple CC Authorizer for token generation and verification.

• multiple CC Authorizer based on the CCAuthorizer interface.
• individual CC Authorizer token expiration configuration.
• Configurable CC token verification frequency.
• critical_level configuration to control Stop_Job or Shutdown_System if CC verification failure.

Sample component config in the "local/resource.json":

{
	"id": "cc_manager",
	"path": "nvflare.app_opt.confidential_computing.cc_manager.CCManager",
	"args": {
		"cc_issuers_conf": [
			{
  				  "issuer_id": "tdx_authorizer",
			  "token_expiration": 250
  				}
		],
		"cc_verifier_ids": ["tdx_authorizer"],
		"verify_frequency": 600,
		"critical_level": 2
	}
},
{
	"id": "tdx_authorizer",
	"path": "nvflare.app_opt.confidential_computing.tdx_authorizer.TDXAuthorizer",
	"args": {
		"tdx_cli_command": "/home/azureuser/TDX/client/tdx-cli/trustauthority-cli",
		"config_dir": "/home/azureuser/NVFlare/nvflare/poc/workspace/server/local"
	}
}

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Quick tests passed locally by running ./runtest.sh.
• In-line docstrings updated.
• Documentation updated.

[chesterxgchen]

add few comments.

Notice there is no unit tests for this PR, we should add some critical ones.

[yanchengnv]

Please see my comments

[YuanTingHsieh]

LGTM, good unit test showcasing how to use Mock in different ways.
Have some questions

[YuanTingHsieh]

LGTM

[yanchengnv]

Some issues I raised about cc_manager.py still are not addressed. Please look into them.

[yhwen]

Some issues I raised about cc_manager.py still are not addressed. Please look into them.

renamed the events to distinguish the events for server and client side.

[yanchengnv]

The event name "PROCEEDED_XXX" isn't what you meant. Should change to PROCESSED_XXX.

[yanchengnv]

LGTM