Optimize AddMasteryEffectOptionsToNode, improve startup time

[Lancej]

Improves startup time by about 400 ms.

AddMasteryEffectOptionsToNode was combining all mastery option mod lines into one node.sd and then calling ProcessStats which led to many mod lines being combined in an attempt to parse them. These combined lines shouldn't be combined for parsing since they come from different mastery options and they also weren't cached so parsing them was very slow.

This change adds a new startIndex parameter to ProcessStats so it can incrementally parse the mastery options as they are added by AddMasteryEffectOptionsToNode instead of parsing them all at once.

Also added new "Startup time: #### ms" print message that measures from start until the first OnFrame call finishes. I was measuring just Main:Init before but there is some init code in the first OnFrame call so now I'm measuring until end of first frame.

Steps taken to verify a working solution:

• Allocating / deallocating mastery nodes still behaves the same
• "Show Node Power" still shows same results
• "Search:" box on passive tree still highlights mastery nodes when it should