Create `UnknownCamelResource` to determine whether the code can be parsed or not

[lordrip]

Please describe the feature that you want to propose

Currently, everything that it's not a Custom Resource, gets parsed as a Camel Route.

The goal for this issue is to fallback to the new UnknownCamelResource so we can properly signal to the user that the code cannot be parsed properly.

In addition to that, in case this UnknownCamelResource is in use, show the corresponding message in the Canvas and avoid modifying the user's source code.