[Parser] Fix parsing of unfinished dot access in string template

Problem appeared in cases like this: "{someVar.}"

#KT-34440 Fixed

compiler/testData/diagnostics/tests/kt34440.fir.kt

@@ -0,0 +1,9 @@
+// ISSUE: KT-34440
+
+class BufferUtil {
+    fun isDirect(cond: Boolean): Boolean =
+        when (cond) {
+            else -> throw Exception("${buf.<!SYNTAX!><!>}")
+        }
+    private class BufferInfo(private val type: Class<*>)
+}

compiler/testData/diagnostics/tests/kt34440.kt

@@ -0,0 +1,9 @@
+// ISSUE: KT-34440
+
+class BufferUtil {
+    fun isDirect(cond: Boolean): Boolean =
+        when (<!UNUSED_EXPRESSION!>cond<!>) {
+            else -> throw Exception("${<!UNRESOLVED_REFERENCE!>buf<!>.<!SYNTAX!><!>}")
+        }
+    private class BufferInfo(private val type: Class<*>)
+}

compiler/testData/diagnostics/tests/kt34440.txt

@@ -0,0 +1,17 @@
+package
+
+public final class BufferUtil {
+    public constructor BufferUtil()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun isDirect(/*0*/ cond: kotlin.Boolean): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    private final class BufferInfo {
+        public constructor BufferInfo(/*0*/ type: java.lang.Class<*>)
+        private final val type: java.lang.Class<*>
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}