Whitelist providers in configuration

[alambare]

Is your feature request related to a problem? Please describe.

It is very frustrating that when we use eodag, all the default providers are enabled. Some even without being configured because they do not need configuration to search. It is hard to have the control of the exact list of providers used.

Describe the solution you'd like

White-listing would provide a robust solution to control used providers even over EODAG updates.

A environement variable called EODAG_PROVIDERS_WHITELIST to whitelist providers in EODAG. Any provider not included in the list would be excluded (even if the provider is configured).

Example:

EODAG_PROVIDERS_WHITELIST=cop_cds,cop_dataspace,creodias

Describe alternatives you've considered

The split of providers into multiple files and removing the files of unwanted providers. However, this keep the burden of maintaining the curated list over EODAG updates.

Additional context

This is particularly useful with stac-fastapi-eodag in production where we want to have the control on providers.