[WIP] Add option to cancel a build

~~this is a rough draft, I'm actively working on it.. so it may throw errors and it may have dirty code.~~

   - Add cancelling and cancelled status for builds
   - Remove pod and update builds to cancelled when a cancel event was triggered for the build
also why we can't have:

```
${KUBE_CMD} cancel-build ${BUILD_NAME} --dump-logs --restart ?
```