unimply demon's_souls -> souls_(series)

BUR #6309 has been approved by @Hillside_Moose.

remove implication demon's_souls -> souls_(series)
mass update demon's_souls souls_(series) -dark_souls_i -dark_souls_ii -dark_souls_iii -> demon's_souls
create alias souls_(series) -> dark_souls_(series)
remove alias dark_souls -> dark_souls_i
create alias dark_souls -> dark_souls_(series)

This implication was done 7 years ago in topic #10342 but it was pretty hastily done and imo it was wrong to do it, because demon's souls at the end of the day has nothing in common with dark souls save for the genre.

Even the examples given in that thread make no sense, because all the mentioned series have a shared world. Dark Souls/Demon Souls are different settings.

I think they did it like this because of the wikipedia page treating both entries as part of the 'Souls' series: https://en.wikipedia.org/wiki/Souls_(series). They share similarities of being made by same developer, being similar in general, and having a shared word, 'souls'. Still, Dark Souls is just a spiritual sequel to Demon Souls, no direct connection between them. The way it is treated now, it would be same as saying Mighty No. 9 is part of the Mega Man franchise, despite being just a spiritual sequel with no direct connections.

The bulk update request #6309 (forum #191658) has been approved by @Hillside_Moose.