Set HTTP User-Agent header for requests

[merkys]

It is usually very nice when software presents itself in the HTTP User-Agent header. Web browsers almost always present themselves in a verbose but neat way. This way the server-side developers are informed about what software makes requests to their servers, and may occasionally forward common issues to the client developers. Moreover, usage statistics could be drawn at the server-size, which is nice.

voila-optimade-client seems to be using Python requests package for HTTP requests. By default its User-Agent is python-requests/<version>. Changing this seems to be rather simple. It would be nice to see voila-optimade-client/<version> at least.

If user privacy is concern, it should not be forgotten that this is F/LOSS, thus anyone concerned with their privacy are free to patch their copy of the client to their liking.