add(option): 'repository_plugin_url' to set the custom plugin repository (plugins.xml) base URL

[Guts]

Description

It allows the user to set it once for all in the config file instead of specifying it for every package command run. It still can be overriden by the -u/--plugin-repo-url CLI option.

Funded by oslandia

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[Guts]

@3nids are you sure to be ok on this one? I feel you a bit frustrated. Do you want me to create an issue with the options renaming project?

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