Water purification tablets now work consistently

[chaosvolt]

Summary

SUMMARY: Balance "Make clean water recipe using purification match efficiency of activating water purifiers"

Purpose of change

Belated followup updates for #2832, making the use of water purification tablets consistent between its iuse and recipe, and other updates.

Describe the solution

1. Changed it so that the clean water recipe using tablets takes 8 water and outputs 8 clean water, as per the ratio its iuse now uses. This also fits even with the water filter items, because those use the exact same use action as the tablets and thus were made 8x as effective too. It even affects vehicle water purifiers.
2. Reduced number of tablets gained from taking apart an MRE from 6 to just 1. Still a net increase from 1.5 liters of water purified to 2 relative to the original amounts, and still solidly a whole day's worth of water according to current game logic when you're expected to tear through not much more than 2 of those a day for most characters.

Describe alternatives you've considered

1. Rigging it to be a less clunky number, not that it matters much since you can just activate the tablets too.
2. Scaling the time up to match what used to be 8 doses worth of the recipe. Not really that worthwhile since the iuse has it only take 2 entire seconds per tablet usage.
3. Converely, making it take more time and nerfing the time cost of the iuse. Since it uses most cost instead of a long action, and allowing it to be interruptible would mean you could magically un-wet your tablets and cancel all progress made in purifying your water (unlike with crafting), this is probably a bad idea for now.
4. Nerfing it down to 1 liter instead of 2 liters for gameplay reasons.
5. Also nerfing how many tablets are in a survival kit. You won't be tearing your way through these like you would MREs so it's probably okay to leave them at the same amount that the bottles typically spawn in.
6. Nerfing the volume of pur tablets so no one will get any wacky ideas about trying to make small bottles hold 100 of them, which would basically cover the water needs of almost any character as permanantly as an infinite water source plus a candle of warding in Arcana does. XD

Testing

1. Checked affected files for syntax and lint errors.
2. Load-tested in compiled build to confirm I can indeed do basic math.
3. Checked to confirm that activating a water purifier or charcoal filter actually did get buffed by Scarf's changes, confirms it only eats 1 charge when doing that.
4. Build a water purifier vehicle to confirm that examining a vehicle purifier also uses only 1 charge to clean up to 2 liters of water.

Additional context

[scarf005]

I Approv