Rethink constraints incorporation

Namely, remove incorporation “otherInsideMyConstraint” to eliminate
constraint system redundancy and produce a potentially very large number
 of constructs.
Instead, introduce not so “spreadable” incorporation during variable
fixation (equality constraint with result type into other constraints).
^KT-41644 Fixed
^KT-42195 Fixed
^KT-42920 Fixed
^KT-42791 Fixed
^KT-41741 Fixed

compiler/testData/diagnostics/testsWithStdLib/inference/performance/kt41741.kt

@@ -0,0 +1,37 @@
+// FIR_IDENTICAL
+// FILE: Simple.java
+// FULL_JDK
+// WITH_RUNTIME
+// !DIAGNOSTICS: -UNUSED_PARAMETER -CAST_NEVER_SUCCEEDS -UNUSED_VARIABLE
+
+import java.util.*;
+import java.util.function.Supplier;
+
+public class Simple<K, V, C extends E, E extends Collection<V>> {
+    public Simple(Map<K, C> backingMap, Supplier<? extends C> innerCollectionCreator) {
+        // TODO
+    }
+    public final void add(K key, V value) {
+        //TODO
+    }
+    public static class ListSimple<K, V> extends Simple<K, V, List<V>, List<V>> {
+        public ListSimple(Map<K, List<V>> backingMap, Supplier<? extends List<V>> innerCollectionCreator) {
+        super(backingMap, innerCollectionCreator);
+    }
+    }
+}
+
+// FILE: main.kt
+import java.util.*
+
+fun <K, V, C : E, E : Collection<V>, B: Simple<K, V, C, E>> Iterable<V>.groupByTo(destination: B, keySelector: (V) -> K) = null as B
+
+enum class Format { Foo, Bar }
+
+class Instance(val format: Format)
+
+fun main(x: List<Instance>) {
+    val doesntWork = x.groupByTo(
+        Simple.ListSimple(EnumMap<Format, List<Instance>>(Format::class.java), ::LinkedList)
+    ) { it.format } // Internal Error occurred while analyzing this expression
+}