remove redundant get_* functions in repo_processor

[maany]

The idea is to incorporate the suggestion made by @snehasi in #27.
Essentially, we should create a function in repo_processor like

def get_repository_file(repo_url, file):
    ...
    ...

The function should get the file (one of meta-info.yaml, config-schema.yaml or default-data.yaml) and return it to the calling function.
In case of meta-info.yaml, it should use the augment_meta_info function to properly format the returned output.
The calling functions in simple_grid_yaml_compiler.py must be appropriately modified.

It's a good step towards improving code quality 👍

[ShemManyu]

Hi @maany currently working on this.
Need some clarification on the file naming. Is the consistency of the file naming ensured i.e meta file will alway be meta-info.yaml and default file will always be site_level_configuration_defaults.yaml ? Thanks

[maany]

Hey @ShemManyu, yes the filenames for component repositories are guaranteed by the framework :)