GuessManagerImpl: support type constrains from DFA, various improvements

Partially fixes IDEA-181794 Suggest completion items with type casts in stream chains if there exists 'filter(x -> x instanceof Foo)' call
Fixes IDEA-182455 Code completion: resolve actual value type assigned to local variable

java/java-tests/testData/codeInsight/completion/normal/AssignmentPreciseTypeDfa.java

@@ -0,0 +1,7 @@
+class Foo {
+    void test(String s) {
+        Object x;
+        x = s;
+        System.out.println(x.subst<caret>);
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/AssignmentPreciseTypeDfa_after.java

@@ -0,0 +1,7 @@
+class Foo {
+    void test(String s) {
+        Object x;
+        x = s;
+        System.out.println(((String) x).substring());
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/DeclarationPreciseTypeDfa.java

@@ -0,0 +1,6 @@
+class Foo {
+    void test(String s) {
+        Object x = s;
+        System.out.println(x.subst<caret>);
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/DeclarationPreciseTypeDfa_after.java

@@ -0,0 +1,6 @@
+class Foo {
+    void test(String s) {
+        Object x = s;
+        System.out.println(((String) x).substring());
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/OptionalDfa.java

@@ -0,0 +1,8 @@
+import java.util.*;
+
+class Foo {
+    void test(Optional<Object> opt) {
+        opt.filter(x -> x instanceof String)
+          .map(s -> s.subst<caret>)
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/OptionalDfa_after.java

@@ -0,0 +1,8 @@
+import java.util.*;
+
+class Foo {
+    void test(Optional<Object> opt) {
+        opt.filter(x -> x instanceof String)
+          .map(s -> ((String) s).substring())
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/StreamDfa.java

@@ -0,0 +1,9 @@
+import java.util.*;
+
+class Foo {
+    void test(List<?> obj) {
+        obj.stream()
+          .filter(x -> x instanceof String)
+          .forEach(e -> e.subst<caret>);
+    }
+}

java/java-tests/testData/codeInsight/completion/normal/StreamDfa_after.java

@@ -0,0 +1,9 @@
+import java.util.*;
+
+class Foo {
+    void test(List<?> obj) {
+        obj.stream()
+          .filter(x -> x instanceof String)
+          .forEach(e -> ((String) e).substring());
+    }
+}