Rework LibGroupTalents now also returns function returns additionally, add Spec Role triggers to load/generic/bt2, fix WeakAuras.GetRegion

- **WeakAuras.SpecForUnit(unit)** = Returns: `classFileName..spec`, `Dominant Tree`, `spent1`, `spent2`, `spent3`
- **WeakAuras.GetUnitRole(unit)** = Returns one of: `"melee"`, `"caster"`, `"healer"`, `"tank"`
- **WeakAuras.SpecRolePositionForUnit(unit)** = Returns: `Dominant Tree`, `spent1`, `spent2`, `spent3`
- **WeakAuras.CheckTalentForUnit(unit, talentId)** = Returns: `"Points spent"` in talent or `nil`
- **WeakAuras.CheckGlyphForUnit(unit, glyphId)** = Returns: `true` if the player has the glyph associated with `spellID` or `spellName`, we can only see the glyphs of players running `LibGroupTalents-1.0`

WeakAurasOptions/BuffTrigger2.lua

@@ -745,6 +745,35 @@ local function GetBuffTriggerOptions(data, triggernum)
                     and not trigger.useActualSpec)
       end
     },
+
+    useGroupRole = {
+      type = "toggle",
+      width = WeakAuras.normalWidth,
+      name = L["Filter by Group Role"],
+      order = 67.1,
+      hidden = function() return
+        not (trigger.type == "aura2" and (trigger.unit == "group" or trigger.unit == "raid" or trigger.unit == "party"))
+      end
+    },
+    group_role = {
+      type = "multiselect",
+      width = WeakAuras.normalWidth,
+      name = L["Group Role"],
+      values = OptionsPrivate.Private.role_types,
+      hidden = function() return
+        not (trigger.type == "aura2" and (trigger.unit == "group" or trigger.unit == "raid" or trigger.unit == "party") and trigger.useGroupRole)
+      end,
+      order = 67.2
+    },
+    group_roleSpace = {
+      type = "description",
+      name = "",
+      order = 67.3,
+      width = WeakAuras.normalWidth,
+      hidden = function() return
+        not (trigger.type == "aura2" and (trigger.unit == "group" or trigger.unit == "raid" or trigger.unit == "party") and not trigger.useGroupRole)
+      end
+    },
     useRaidRole = {
       type = "toggle",
       width = WeakAuras.normalWidth,