Code style: add option for blank lines before declarations

#KT-39024 Fixed
#KT-37420 Fixed
#KT-37891 Fixed

idea/testData/formatter/EmptyLineBetweeMultilineDeclarationTwo.kt

@@ -0,0 +1,316 @@
+interface Some {
+    fun f1()
+    fun f2()
+    fun f3()
+    /* test */
+    fun f4()
+    /* test */ fun f5()
+    /**
+     * test
+     * 2
+     */
+    fun f6()
+    fun f7()
+    @NotNull
+    fun f8()
+    fun f9()
+}
+
+interface Some2 {
+    fun f1()
+    fun f2()
+    fun f3()
+    @Ann
+    fun f4()
+    @Ann fun f5()
+    @Ann(
+        42
+    )
+    fun f6()
+    fun f7()
+    @NotNull
+    fun f8()
+    fun f9()
+}
+
+abstract class Abstract() {
+    abstract fun f1()
+    abstract fun f2()
+    // test
+    abstract fun f3()
+    // test
+    /* test */ abstract fun f4()
+    abstract fun f5()
+    abstract fun f6()
+    /* test */ abstract fun f7()
+}
+
+abstract class Abstract() {
+    abstract fun f1()
+    abstract fun f2()
+    @Ann
+    abstract fun f3()
+    @Ann
+    @Ann abstract fun f4()
+    abstract fun f5()
+    abstract fun f6()
+    @Ann abstract fun f7()
+}
+
+fun f1() {}
+class C1 {}
+
+// -----
+
+fun f2() {}
+class C2
+
+// -----
+
+// test
+fun f3 = 1
+class C3 {}
+
+// -----
+
+/*test*/
+fun f4 = 2
+class C4
+
+// -----
+
+@Ann
+fun f3 = 1
+class C3 {}
+
+// -----
+
+@Ann
+fun f4 = 2
+class C4
+
+// -----
+
+class C5 {}
+fun f5() {}
+
+// -----
+
+class C6
+fun f6() {}
+
+// -----
+
+class C7 {}
+fun f7 = 1
+
+// -----
+
+class D {
+
+}
+class E
+    : Some
+class F
+
+@Ann
+fun some() = 1
+class G
+fun some() = 1
+
+val a = 1
+class H
+val b = 1
+
+// No lines
+fun f1() {}
+val p1 = 1
+fun f2() {}
+
+@Ann
+fun f3() = 1
+val p2 = 1
+fun f4() = 1
+
+fun f4() {}
+val p3: Int
+    get() = 1
+fun f5() = 1
+
+class OneLine {
+    fun f1() {}
+
+    val p1 = 1
+
+    fun f2() {}
+
+    fun f3() = 1
+
+    val p2 = 1
+
+    fun f4() = 1
+
+    fun f4() {}
+
+    val p3: Int
+        get() = 1
+
+    fun f5() = 1
+}
+
+class TwoLines {
+    fun f1() {}
+
+
+    val p1 = 1
+
+
+    fun f2() {}
+
+
+    fun f3() = 1
+
+
+    val p2 = 1
+
+
+    fun f4() = 1
+
+
+    fun f4() {}
+
+
+    val p3: Int
+        get() = 1
+
+
+    fun f5() = 1
+}
+
+// No lines between
+
+fun f2() {}
+fun f1() {}
+fun f3() = 1
+fun f4() {}
+fun f5() {
+}
+fun f6() = 1
+fun f7() = 8
+
+// One line
+
+fun f2() {}
+
+fun f1() {}
+
+fun f3() = 1
+
+fun f4() {}
+
+fun f5() {
+}
+
+fun f6() = 1
+
+fun f7() = 8
+// test
+fun f8() = 42
+
+// Two lines between
+fun l1() {}
+
+
+fun l2() {}
+
+
+fun l3() = 1
+
+
+fun l4() {}
+
+
+fun l5() {
+}
+
+
+fun l6() = 1
+
+
+fun l7() = 8
+
+// test
+val p1 by Some
+val p2 = 1
+val p3: Int get() = 3
+val p4: Int
+    get() { return 1 }
+val p5: Int
+
+class OneLine {
+    val p1 by Some
+
+    val p2 = 1
+
+    val p3: Int get() = 3
+
+    val p4: Int
+        get() { return 1 }
+
+    val p5: Int
+}
+
+class TwoLines {
+    val p1 by Some
+
+
+    val p2 = 1
+
+
+    val p3: Int get() = 3
+
+
+    val p4: Int
+        get() { return 1 }
+
+
+    val p5: Int
+}
+
+class Some(b: Boolean) {
+    // Comment.
+    constructor(b: Int) : this(b == 0)
+    /**
+     * test
+     * 2
+     */
+    constructor(b: String) : this(b.isEmpty())
+    constructor(b: Long) : this(b == 0L)
+    @Ann
+    constructor(b: Int) : this(b == 0)
+    @Ann(
+        42
+    )
+    constructor(b: String) : this(b.isEmpty())
+    constructor(b: Long) : this(b == 0L)
+}
+
+enum class TestEnum {
+    /** A comment for the item #1. */
+    ITEM1,
+    /** A comment for the item #2. */
+    ITEM2,
+    /** A comment for the item #3. */
+    ITEM3
+}
+
+class Foo {
+    @Inject
+    lateinit var logger: Logger
+    @Inject
+    lateinit var userService: UserService
+    @Inject
+    override lateinit var configBridge: ConfigBridge
+}
+
+// SET_INT: BLANK_LINES_BEFORE_DECLARATION_WITH_COMMENT_OR_ANNOTATION_ON_SEPARATE_LINE = 2