broadcast: add complex leaderboard

[ralphptorres]

some tourneys, like norway and poland, use unique scoring systems that are not really so complex. in most cases, scores can be fully described by a linear equation where coefficients act as weights or multipliers. this feature should also be able to handle tiebreak scoring assuming tb scores are numerical. this request proposes

• interface for table manipulation to fill in row values (mostly frequency) that are to be weighted/multiplied
• weight or multiplier assignment to specific cols
• auto total score calculation in a designated col
• good ole player data including rank, name, elo, perf.

since the first item is difficult and adds unnecessary complexity, an alternative approach is proposed

[ralphptorres]

possible dupe of #15396