fix: Small type improvements

[vonagam]

• getStrategies in AuthenticationBase does not return undefined values.
• export ConnectionEvent in @feathersjs/authentication.
• Date.now() instead of new Date().getTime().
• Add authenticated to Params definition.
• Do not use _.get where simply getting property works.
• Type numbered errors in @feathersjs/errors.
• Continuing fix: Typings for express request and response properties #1609, extend express application type with feathers application.
• Reverting one change in fix: Small improvements #1605, add AuthenticationService extends ServiceAddons<AuthenticationResult> to use .hooks and .publish on a service instance.
• Type methods in a service.
• Type httpMethod for express rest.