Pure CMake component dependencies

[malachib]

I'm exploring "pure" CMake components (libraries only) as per
https://docs.espressif.com/projects/esp ... components

Two related issues I face:

1. Cannot make it interact with IDF component manager
2. If main consuming app uses `COMPONENTS main` then pure cmake component can't find things like `idf::nvs_flash`

What do you recommend to overcome these issues, especially #1
Placing dependency management out in consuming app feels more like a workaround than a solution