[FIR] Implement FirReturnAllowedChecker

Supported diagnostics:
- RETURN_NOT_ALLOWED
- RETURN_IN_FUNCTION_WITH_EXPRESSION_BODY

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

@@ -1,4 +1,4 @@
-fun <T> simpleRun(f: (T) -> Unit): Unit = f(return)
+fun <T> simpleRun(f: (T) -> Unit): Unit = f(<!RETURN_IN_FUNCTION_WITH_EXPRESSION_BODY!>return<!>)
 
 fun <T, R> List<T>.simpleMap(f: (T) -> R): R {
 

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

@@ -0,0 +1,10 @@
+FILE: labeledReturnFromNotLabeledUnnamedFunction.kt
+    public final fun notInline(block: R|(kotlin/Boolean) -> kotlin/Unit|): R|kotlin/String| {
+        ^notInline String()
+    }
+    public final fun test(): R|kotlin/String| {
+        ^test R|/notInline|(fun <anonymous>(b: R|kotlin/Boolean|): R|kotlin/Unit| <inline=NoInline>  {
+            ^@notInline Unit
+        }
+        )
+    }

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

@@ -0,0 +1,9 @@
+fun notInline(block: (Boolean) -> Unit): String {
+    return ""
+}
+
+fun test(): String {
+    return notInline(fun(b: Boolean) {
+        return@notInline
+    })
+}