io/pointer,io/router: [API] make pass-through a property of AreaOp

We're about to make operation scopes explicit, which would result in
both AreaOp and PassOp be scoped. However, PassOp seems to light to have
its separate stack, so this change instead makes pass-through a property
of an area. We're assuming that clients that want pass-through are also
aware of the affected hit area.

API change: replace PassOps with the AreaOp.PassThrough field.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

internal/opconst/ops.go

@@ -19,7 +19,6 @@ const (
 	TypeLinearGradient
 	TypeArea
 	TypePointerInput
-	TypePass
 	TypeClipboardRead
 	TypeClipboardWrite
 	TypeKeyInput
@@ -45,9 +44,8 @@ const (
 	TypePaintLen           = 1
 	TypeColorLen           = 1 + 4
 	TypeLinearGradientLen  = 1 + 8*2 + 4*2
-	TypeAreaLen            = 1 + 1 + 4*4
+	TypeAreaLen            = 1 + 1 + 1 + 4*4
 	TypePointerInputLen    = 1 + 1 + 1 + 2*4 + 2*4
-	TypePassLen            = 1 + 1
 	TypeClipboardReadLen   = 1
 	TypeClipboardWriteLen  = 1
 	TypeKeyInputLen        = 1 + 1
@@ -90,7 +88,6 @@ func (t OpType) Size() int {
 		TypeLinearGradientLen,
 		TypeAreaLen,
 		TypePointerInputLen,
-		TypePassLen,
 		TypeClipboardReadLen,
 		TypeClipboardWriteLen,
 		TypeKeyInputLen,
@@ -142,8 +139,6 @@ func (t OpType) String() string {
 		return "Area"
 	case TypePointerInput:
 		return "PointerInput"
-	case TypePass:
-		return "Pass"
 	case TypeClipboardRead:
 		return "ClipboardRead"
 	case TypeClipboardWrite: