Extend verbosity of migration framework

### What problem are you facing?

Currently while working on migrator and having some bug in the source sample, I am getting
```
go run ./cmd/migrator/main.go -s ./source
Using filesystem source
main: error: Failed to generate the migration plan: failed to generate the migration plan: failed to migrate resource: failed to migrate resource: failed to convert from unstructured.Unstructured to the managed resource type: unrecognized type: string
exit status 1
```
It is not clear where it is happening

### How could Upjet help solve your problem?

Increase error verbosity, provide some context and hints around the place of failure