Add custom symbol model for index

Author: fwcd

server/src/main/kotlin/org/javacs/kt/index/Symbol.kt

@@ -0,0 +1,16 @@
+package org.javacs.kt.index
+
+import org.jetbrains.kotlin.name.FqName
+
+data class Symbol(
+    // TODO: Store location (e.g. using a URI)
+    private val fqName: FqName,
+    private val kind: Kind
+) {
+    enum class Kind {
+        CLASS,
+        INTERFACE,
+        FUNCTION,
+        VARIABLE
+    }
+}