[APPROVED] Fixing Half-Life Series Tagging

remove implication half-life_2 -> half-life
create implication half-life -> half-life_(series)
create implication half-life_2 -> half-life_(series)
create implication half-life_3 -> half-life_(series)

Link to request

Before this, half-life was used for both the series and the first game. With this, we will be able to tag the individual games separately.

EDIT: The bulk update request #1518 (forum #144095) has been approved by @Hillside_Moose.

The bulk update request #1518 (forum #144095) has been approved by @Hillside_Moose.

Since they're numerical sequels instead of idiosyncratic ones like the Tales games, half-life is the series tag while half-life_1 will be the tag for anything referencing the first game.