K2: Implement partially constrained lambda analysis (PCLA)

It's expected to partially mimic the behavior of what
previously was called builder inference, but with more clear contracts
(documentation is in progress, though)

See a lot of fixed issues in the later commits with test data,
especially [red-to-green]

^KT-59791 In Progress

.idea/dictionaries/Denis_Zharkov.xml

@@ -0,0 +1,7 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="Denis.Zharkov">
+    <words>
+      <w>pcla</w>
+    </words>
+  </dictionary>
+</component>