SC2: Rebalance item classes

[Ziktofel]

Sets Advanced Medic Facilities (Medic) to filler as:
This item is never useful to get out of BK and is never part of logic

Sets these items for useful:

• Fire-Suppression System (Building)
• Cellular Reactor
• Regenerative Bio-Steel
  As these items are more useful than others in filler class

[Magnemania]

@TheCondor07 You are the maintainer for this world, so we'd like you to approve this.

Some context for anyone reading this PR:

StarCraft II has no natural filler items whatsoever; every item in the game has some situational purpose and is nonreplenishable. TheCondor created three filler items specifically for the randomizer (+15 Starting Minerals/Vespene and +2 Starting Supply), but there's only room for about 5? of them in the vanilla location pool.

To compensate for this skewed ratio compared to other AP games, less useful items are classified as filler; this is comparable to how the SM AP randomizer classifies many of its Missiles/Super Missiles/Power Bombs as filler despite those items being valuable in the game and potentially even affecting progression. It makes it possible for a StarCraft player to exclude locations, and in a multiworld context, it ensures that excluded locations across the multiworld won't have a bias towards non-SC2 players (sucking up all of the rupees, missiles, and emblems that would let the players in those worlds finish their games faster).

It is less important to classify items as filler now that SC2 settings allow the player to customize their item and location pool; they have a limited ability to remove checks that they don't want to complete from the game entirely, and can remove items that would be replaced with filler items if the location pool is large enough. However, in the specific case of Advanced Medic Facilities, I believe it does deserve the filler designation for these reasons:

• Advanced Medic Facilities allows players to build Medics without a Tech Lab. Of the infantry units that Medics can support, only 1/6 does not also require a tech lab to be built, so if the player has not received that particular item they're going to be building Tech Labs anyways.
• The Tech Reactor item almost eclipses Advanced Medic Facilities, as it removes the Tech Lab from the game. There is still one use case for Advanced Medic Facilities with both items (building Medics from a Barracks with no add-on at all) but this is a rare one, as most players will immediately build a Tech Reactor at the very start of the mission in order to double production speed.
• There are quite a few other unique items currently classified as filler that are far more universally useful than Advanced Medic Facilities, such as Cellular Reactor and Regenerative Bio-Steel (both of which were placed as major rewards in the vanilla game).

I approve of this PR, but Condor should see it. I also think it might be better to make this a general filler/useful reclassification PR, these items 'ought to be classified as Useful for their tendency to always be useful in AP regardless of which other items have been received:

• Fire-Suppression System (Building)
• Cellular Reactor
• Regenerative Bio-Steel

[Ziktofel]

Added these items, tested by generating a game. Title and description updated

[Magnemania]

I support these changes. Still need Condor's approval.