Buff UEF ACU Drone's rebuild costs

[lL1l1]

Description of the proposed changes

• Closes [Balance Idea]: Balance C-D1 rebuild cost #6553.
  • "Time cost: 100->200" is interpreted as coming from the default 10 buildpower being multiplied with the 10 seconds of the economy event, so that's how the 100 build time exists despite the actual build time in the drone blueprint being 400.
• The drone build time is now affected by the ACU's buildpower.

Testing done on the proposed changes

Spawn ACUs, upgrade the drone upgrades and various build suite levels. Kill the drones so that they rebuild.
Drones rebuild at a reasonable consumption at T1, and speed up when rebuilt with T2/T3 upgrades. The consumption at higher speeds is still less than any available structures, so the economy being unable to support the consumption rate is not an issue.

   CreateUnitAtMouse('xrb0304', 0,   -1.34,   -6.15,  0.00000)
   CreateUnitAtMouse('xrb0304', 0,   -1.34,   -4.15,  0.00000)
   CreateUnitAtMouse('xrb0304', 0,   -0.34,    5.85,  0.00000)
   CreateUnitAtMouse('uel0001', 0,    3.94,    0.48, -0.04558)
   CreateUnitAtMouse('uel0001', 0,    2.90,   -4.92, -2.31662)
   CreateUnitAtMouse('xab1401', 0,   -7.34,    1.85,  0.00000)
   CreateUnitAtMouse('uel0001', 0,    5.89,    3.61, -0.76593)
   CreateUnitAtMouse('xrb0304', 0,   -0.34,    3.85,  0.00000)
   CreateUnitAtMouse('xrb0304', 0,   -0.34,    1.85, -0.00000)
   CreateUnitAtMouse('xrb0304', 0,   -0.34,   -0.15,  0.00000)
   CreateUnitAtMouse('xrb0304', 0,   -1.34,   -2.15,  0.00000)

Additional context

• After testing the rebuilding during a stall, it seems like CreateEconomyEvent works in blocks of buildtime in the same way as silos. Reworking the drone rebuild process to be the same as the kennel's (TPodTowerUnit) would fix this.
• The Drone auto-rebuild toggle is still using the very old gpg system of removing the drone enhancement when the drone dies. To implement it correctly there would have to be some UI data set on the ACU to create a "rebuild drone" button when the drone is destroyed but not rebuilding, and then that button would issue a sim callback or script task order that initiates the drone rebuild sim-side.

Checklist

• Changes are annotated, including comments where useful
• Changes are documented in the changelog for the next game version

[lL1l1]

@clyfordv I think you would be interested in the various possible implementations for improving drone rebuilding, which is related to this PR. I did mention that kennels have their own special way of building drones, but there's also external factories and unit upgrades which might be interesting to make it possible to assist the drone reconstruction and even display the rebuild progress separately from the ACU.