Add code/test coverage support upon PR creation

[Kailai-Wang]

It would be good to have an automated test coverage report, especially for our own pallets.

Tools:

• https://about.codecov.io/
• https://github.com/xd009642/tarpaulin
• https://github.com/actions-rs/tarpaulin

A sharing session is worth it.

[Kailai-Wang]

An example of the codecov report from Acala:

[github-actions[bot]]

:exclamation: This issue is stale because it has been open for 20 days with no activity. Remove S2-stale label or update it, otherwise this issue will be closed in 5 days. @litentry/parachain

[github-actions[bot]]

:exclamation: This issue is stale because it has been open for 20 days with no activity. Remove S2-stale label or update it, otherwise this issue will be closed in 5 days. @litentry/parachain

[github-actions[bot]]

:exclamation: This issue is stale because it has been open for 60 days with no activity. Remove S2-stale label or update it, otherwise this issue will be closed in 7 days. @litentry/parachain

[Kailai-Wang]

This ticket needs to be resolved in the near future as well

[BillyWooo]

https://codecov.io/github/litentry/litentry-parachain/commit/1976048b10a79e6ff809bf9bada35126ac6a1f8a

https://github.com/litentry/litentry-parachain/pull/658