Add lifespan support

[aemr3]

Added support for lifespan functions. Previously it wasn’t working because we are removing default router from kwargs while cloning the app.

[alexschimpf]

@aemr3 Your commit messages fail the commitlint checks, but I'll just squash your commits into a properly formatted commit.

[alexschimpf]

:tada: This PR is included in version 2.1.3 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: