Add localisation support to short relative timestamps on score leaderboards

[Newmcpe]

Closes #38065.

Relative timestamps on score leaderboards ("4d", "9mo", "1y") were hardcoded to English rather than going through localisation, so non-English clients showed untranslated text while the hover tooltip was already localised. Reuses osu-web's existing common.scoreboard_time.* strings (same ones the in-game web views use) instead.

Before	After

[bdach]

This PR changes the formatting of timestamps in English.

before	after

Previously the client formatting was intentionally deviated from the website's.

Deviations of particular note:

• The English copy does not use plural forms at all

• The English copy translates any numbers of seconds or minutes (any timespans below an hour) to now. As it turns out, translations take weird liberties and instead display the actual number of seconds or minutes. The game was attempting to reimplement this via the lowerCutoff argument of ToShortRelativeTime().

  This is relevant, because now if the web translations are used by the game directly, the local leaderboard in English will start showing timestamps of now for any score set within the last hour.

Before this can proceed, this entire mess probably needs to be cleared up and unified, one way or another.