KDoc link parsing rewrite.

Support qualified names immediately after tag (@see or @param). Detect whether a tag is followed by a reference immediately while lexing, remove TEXT_OR_LINK token type. Remove duplicate nested KDocLink nodes from the PSI structure.

idea/testData/kdoc/resolve/SeeReference.kt

@@ -0,0 +1,12 @@
+/**
+ * @see Foo.ba<caret>r
+ */
+fun xyzzy() {
+}
+
+class Foo {
+    fun bar() {
+    }
+}
+
+// REF: (in Foo).bar()