Add support to take into account empty sockets when assuming socketed

Check version

• I'm running the latest version of Path of Building and I've verified this by checking the changelog

Check for duplicates

• I've checked for duplicate issues by using the search function of the issue tracker

Check for support

• I've checked that the calculation is supposed to be supported. If it isn't please open a feature request instead (Red text is a feature request).

What is the value from the calculation in-game?

In game my Total Health value is 19243. In my build I have 17 empty red sockets, 0 empty green sockets, 0 empty blue sockets, and 0 empty white sockets. This leads to Untouched Soul granting (17 * 40) max life (total 680) and after everything else in the build brings the total to 19243.

What is the value from the calculation in Path of Building?

In Path of Building, my Total Health value shows 18763. Without setting additional configuration options to overwrite the expected sockets from Untouched Soul, PoB calculates 600 max life, 40 max mana, and 225 accuracy rating. This would be the result of 15 empty red sockets, 1 empty green sockets, 1 empty blue sockets, and 0 empty white sockets. This leads to Untouched Soul granting (15 * 40) max life (total 600) instead of the correct (17 * 40) max life from empty red sockets.

The issue as far as I can determine is because of the order of the sockets on my Body Armour which is socketed as Red Red Red Red Green Blue or RRRRGB. I have 4 gems socketed in the lower half of the chest piece leaving the first two red sockets free. It seems that the 4 skill gems in the item are socketed in the first 4 slots regardless of color instead of skill gems adhering to their color (since green and blue are spots 5 & 6 in this case respectively)

How to reproduce the issue

1. Equip "The Untouched Soul, Gold Amulet"
2. Using a 6 socket (links not important) body armour, place gems in any of the lower sockets but NOT the first two sockets.
3. At this point PoB will have calculated the stats from Untouched Soul wrong because when 4 items are socketed in the body armour they are assumed to be be in the first available sockets (color doesn't seem to matter)

Character build code

https://pobb.in/88G9VsD9oTih

Screenshots

リンクされたpobb.inのビルドを使用し、The Untouched Soulと、下側のソケットにジェムが入っている6ソケットの胴体防具を使って再現手順に従ってください。PoBが想定する空のソケットの色と、それによって算出されるThe Untouched Soulのステータスをゲーム内の値と比較します。ソケットの位置に関係なく、実際に空いているソケットが計算に含まれれば完了です。