Network page filters in URL

[MartinKolarik]

https://globalping.io/network

Store the current filter in the URL to support links like ?filter=europe,eyeball-network

[MartinKolarik]

@mpourismaiel please self-assign after you accept the repo invite. I added part of this in gh-707 branch but it needs a bit of refactoring to actually apply the value on page load.