[FIR] Add checking receivers of callable references

compiler/fir/analysis-tests/testData/resolveWithStdlib/callableReferences/genericInReceiver.kt

@@ -0,0 +1,7 @@
+fun test_1(a: String, s: String) {
+    val pair = s.let(a::to)
+}
+
+fun test_2(a: String, s: String) {
+    val pair = s.let { a.to(it) }
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/callableReferences/genericInReceiver.txt

@@ -0,0 +1,10 @@
+FILE: genericInReceiver.kt
+    public final fun test_1(a: R|kotlin/String|, s: R|kotlin/String|): R|kotlin/Unit| {
+        lval pair: R|kotlin/Pair<kotlin/String, kotlin/String>| = R|<local>/s|.R|kotlin/let|<R|kotlin/String|, R|kotlin/Pair<kotlin/String, kotlin/String>|>(R|<local>/a|::R|kotlin/to<kotlin/String, kotlin/String>|)
+    }
+    public final fun test_2(a: R|kotlin/String|, s: R|kotlin/String|): R|kotlin/Unit| {
+        lval pair: R|kotlin/Pair<kotlin/String, kotlin/String>| = R|<local>/s|.R|kotlin/let|<R|kotlin/String|, R|kotlin/Pair<kotlin/String, kotlin/String>|>(<L> = let@fun <anonymous>(it: R|kotlin/String|): R|kotlin/Pair<kotlin/String, kotlin/String>| <kind=EXACTLY_ONCE>  {
+            ^ R|<local>/a|.R|kotlin/to|<R|kotlin/String|, R|kotlin/String|>(R|<local>/it|)
+        }
+        )
+    }