Data class rule: removing several cases from the scope of the inspection

### What's done:
- Removed annotation, value, sealed, inline, inner classes from the scope
- Added tests

diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter6/classes/DataClassesRule.kt

@@ -42,11 +42,10 @@ class DataClassesRule(configRules: List<RulesConfig>) : DiktatRule(
     }
 
     private fun handleClass(node: ASTNode) {
-        with((node.psi as KtClass)) {
-            if (isData() || isInterface()) {
-                return
-            }
+        if ((node.psi as KtClass).isDefinitelyNotADataClass()) {
+            return
         }
+
         if (node.canBeDataClass()) {
             raiseWarn(node)
         }
@@ -128,6 +127,12 @@ class DataClassesRule(configRules: List<RulesConfig>) : DiktatRule(
         return true
     }
 
+    /** we do not exclude inner classes and enums here as if they have no
+     * methods, then we definitely can refactor the code and make them data classes
+     **/
+    private fun KtClass.isDefinitelyNotADataClass() =
+        isValue() || isAnnotation() || isInterface() || isData() || isSealed() || isInline() || isInner()
+
     @Suppress("UnsafeCallOnNullableType")
     private fun areGoodAccessors(accessors: List<ASTNode>): Boolean {
         accessors.forEach {

diktat-rules/src/test/kotlin/org/cqfn/diktat/ruleset/chapter6/DataClassesRuleWarnTest.kt

@@ -288,6 +288,58 @@ class DataClassesRuleWarnTest : LintTestBase(::DataClassesRule) {
         )
     }
 
+    @Test
+    @Tag(USE_DATA_CLASS)
+    fun `annotation classes bug`() {
+        lintMethod(
+            """
+                |@Retention(AnnotationRetention.SOURCE)
+                |@Target(AnnotationTarget.CLASS)
+                |annotation class NavGraphDestination(
+                |    val name: String = Defaults.NULL,
+                |    val routePrefix: String = Defaults.NULL,
+                |    val deepLink: Boolean = false,
+                |) {
+                |    object Defaults {
+                |        const val NULL = "@null"
+                |    }
+                |}
+            """.trimMargin()
+        )
+    }
+
+    @Test
+    @Tag(USE_DATA_CLASS)
+    fun `value or inline classes bug`() {
+        lintMethod(
+            """
+                |@JvmInline
+                |value class Password(private val s: String)
+                |val securePassword = Password("Don't try this in production")
+            """.trimMargin()
+        )
+    }
+
+    @Test
+    @Tag(USE_DATA_CLASS)
+    fun `sealed classes bug`() {
+        lintMethod(
+            """
+                |sealed class Password(private val s: String)
+            """.trimMargin()
+        )
+    }
+
+    @Test
+    @Tag(USE_DATA_CLASS)
+    fun `inner classes bug`() {
+        lintMethod(
+            """
+                |inner class Password(private val s: String)
+            """.trimMargin()
+        )
+    }
+
     @Test
     @Tag(USE_DATA_CLASS)
     fun `shouldn't trigger on interface`() {