K2: Refine handling of Delegate resolution mode

- Move it out of the ContextDependent hierarchy
- Get rid of many controversial checks that were necessary because
Delegate was a ContextDependent inheritor
- Actually fix semantics for lambda processing

Previously, lambdas as delegate expression were not being analyzed
thus leading to an exception (see KT-64635), and this change
forces analyzing them in the same mode as ContextIndependent
(thus `{}` made by default `() -> Unit` leaving to DELEGATE_SPECIAL_FUNCTION_MISSING)

Before this change, new test was failing with an exception.

I've analyzed all `is ContextDependent` and it seems that none of them
is relevant to delegates.

^KT-64635 Fixed

compiler/testData/diagnostics/tests/delegatedProperty/inference/lambdaDelegate.kt

@@ -0,0 +1,38 @@
+// ISSUE: KT-64635
+// FIR_IDENTICAL
+import kotlin.reflect.KProperty
+
+class Context
+
+interface MyReadOnlyProperty<in T, out V> {
+    operator fun getValue(thisRef: T, property: KProperty<*>): V
+}
+
+open class NodeHolder {
+    operator fun ((Context).() -> Unit).provideDelegate(
+        thisRef: Any?,
+        prop: KProperty<*>
+    ): MyReadOnlyProperty<Any?, Unit> = TODO()
+}
+
+class SubClass1 : NodeHolder() {
+    val foo: (Context).() -> Unit = {}
+    val x by foo
+}
+
+class SubClass2 : NodeHolder() {
+    val x by <!DELEGATE_SPECIAL_FUNCTION_MISSING!>{}<!>
+}
+
+fun main() {
+    val my_holder_works =
+        object : NodeHolder() {
+            val foo: (Context).() -> Unit = {}
+            val x by foo
+        }
+
+    val my_holder_bad =
+        object : NodeHolder() {
+            val x by <!DELEGATE_SPECIAL_FUNCTION_MISSING!>{}<!>
+        }
+}