More robust handling of deprecated pragmas (#8696)

Prevent `deprecated` annotations to "slip" up to the parent module and
warn about unsupported annotations.

Accidentally fixes #7867

tests/deprecated/importme.nim

@@ -0,0 +1,10 @@
+type
+  Ty* {.deprecated.} = uint32
+  Ty1* {.deprecated: "hello".} = uint32
+
+var aVar* {.deprecated.}: char
+
+proc aProc*() {.deprecated.} = discard
+proc aProc1*() {.deprecated: "hello".} = discard
+
+{.deprecated: "goodbye".}