PathConfigPane: Eliminate main frame global usage

[lioncash]

UI event systems are made specifically to avoid this sort of coupling between window types, so we may as well use it.

---

This change is

[dolphin-emu-bot]

FifoCI detected that this change impacts graphical rendering. Here are the behavior differences detected by the system:

• aeon-charge-attack on ogl-lin-mesa: diff
• cel-damage-lighting on ogl-lin-mesa: diff
• ed-updated on ogl-lin-mesa: diff
• fishing-resort-map on ogl-lin-mesa: diff
• fsa-layers on ogl-lin-mesa: diff
• hb-discgolf on ogl-lin-mesa: diff
• jj-awae-mirrored on ogl-lin-mesa: diff
• last-story-shadows on ogl-lin-mesa: diff
• melee-lighting on ogl-lin-mesa: diff
• mii-channel on ogl-lin-mesa: failed to render
• mkwii-bluebox on ogl-lin-mesa: diff
• nddemo-lighting on ogl-lin-mesa: diff
• nes-vc on ogl-lin-mesa: diff
• pw-black-bars on ogl-lin-mesa: diff
• rs2-skybox on ogl-lin-mesa: diff
• rs3-skybox2 on ogl-lin-mesa: diff
• simpsons-game on ogl-lin-mesa: diff
• smg-marioeyes on ogl-lin-mesa: diff
• soa-black on ogl-lin-mesa: diff
• soniccolors-mm on ogl-lin-mesa: diff
• spyro-bloom on ogl-lin-mesa: diff
• spyro-depth on ogl-lin-mesa: diff
• ssbm-pointsize on ogl-lin-mesa: failed to render
• super-sluggers-white-out on ogl-lin-mesa: diff
• thps3-earlyz on ogl-lin-mesa: failed to render
• xenoblade-menu on ogl-lin-mesa: failed to render
• zelda1-vc on ogl-lin-mesa: diff

_{^{automated-fifoci-reporter}}

[BhaaLseN]

---

Reviewed 4 of 4 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

---

Comments from Reviewable