Support deprecation level HIDDEN for classifiers

Classifiers annotated with `@Deprecated(level = HIDDEN)` now have smaller
priority in imports, similarly to private classes. For example, if two
classifiers named Foo are imported with a star import and one of them is
deprecated-hidden, the name Foo in the source code is resolved to the other
one.

Also a minor change in multi-module diagnostic tests: do not append newlines
after the last module in the test

 #KT-13926 Fixed

compiler/testData/diagnostics/tests/deprecated/deprecatedHidden.kt

@@ -0,0 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+@Deprecated("", level = DeprecationLevel.HIDDEN)
+open class Foo
+
+fun test(f: <!DEPRECATION_ERROR!>Foo<!>) {
+    f.toString()
+    val g: <!DEPRECATION_ERROR!>Foo<!>? = <!UNRESOLVED_REFERENCE!>Foo<!>()
+}
+
+class Bar : <!UNRESOLVED_REFERENCE, DEPRECATION_ERROR, DEBUG_INFO_UNRESOLVED_WITH_TARGET!>Foo<!>()

compiler/testData/diagnostics/tests/deprecated/deprecatedHidden.txt

@@ -0,0 +1,17 @@
+package
+
+public fun test(/*0*/ f: Foo): kotlin.Unit
+
+public final class Bar : Foo {
+    public constructor Bar()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+@kotlin.Deprecated(level = DeprecationLevel.HIDDEN, message = "") public open class Foo {
+    public constructor Foo()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}