Fix: Enable alpha style filter action for nameplates

[Xurkon]

Summary

This PR fixes the Non-Target Alpha style filter that was reported as non-functional in issue #101.

Root Cause

The alpha style filter action code in \StyleFilter.lua\ (lines 558-561) was commented out, preventing any alpha transparency changes from being applied to nameplates.

Changes Made

• Uncommented lines 558-561 in \ElvUI/Modules/NamePlates/StyleFilter.lua`n- This enables the \mod:PlateFade()\ call that applies alpha transparency to nameplates

Testing Recommendations

1. Create a nameplate style filter with an alpha value (e.g., 50%)
2. Apply the filter to any nameplate trigger condition
3. Verify that the nameplate transparency changes in real-time when the filter is active
4. Test with '/reload' to ensure changes persist

Related Issue

Fixes #101

[Xurkon]

As described.