MET Trigger: AthenaMT algorithms for clusters and jets

Initial implementations of MET from clusters (ATR-19491) and MET from jets (ATR-19490). This MR replaces !21830 (closed) and !21824 (closed), and resolves the conflicts that would have arisen if they were merged together.

Standalone job options and ctests are implemented for these algorithms in TrigUpgradeTest. Integration into TrigUpgradeTest/met.menu.py to follow later this week as part of the Trigger AthenaMT hackathon.

Developed together with @khamano.