FIR: Fix label/receiver for lambda within infix calls

While this fix only changes label name, it's important for proper
lambda resolution because receiver is set for a lambda
only in presence of a label

This commit fixes a lot of checkType calls in diagnostic tests

compiler/fir/analysis-tests/testData/resolve/labelAndReceiverForInfix.kt

@@ -0,0 +1,14 @@
+class A {
+    fun bar() {}
+}
+
+infix fun (() -> Unit).foo(x: A.() -> Unit) {}
+
+fun main() {
+    {
+        return@foo
+    } foo {
+        bar()
+        return@foo
+    }
+}

compiler/fir/analysis-tests/testData/resolve/labelAndReceiverForInfix.txt

@@ -0,0 +1,22 @@
+FILE: labelAndReceiverForInfix.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun bar(): R|kotlin/Unit| {
+        }
+
+    }
+    public final infix fun R|() -> kotlin/Unit|.foo(x: R|A.() -> kotlin/Unit|): R|kotlin/Unit| {
+    }
+    public final fun main(): R|kotlin/Unit| {
+        foo@fun <anonymous>(): R|kotlin/Unit| {
+            ^@foo Unit
+        }
+        .R|/foo|(foo@fun R|A|.<anonymous>(): R|kotlin/Unit| {
+            this@R|special/anonymous|.R|/A.bar|()
+            ^@foo Unit
+        }
+        )
+    }