Intentions: Implement intention to replace camel-case test function name with a space-separated one

#KT-12489 Fixed
(cherry picked from commit 21e24a1)

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/.intention

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.intentions.ConvertCamelCaseTestFunctionToSpacedIntention

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/letters.kt_ignored

@@ -0,0 +1,12 @@
+// CONFIGURE_LIBRARY: JUnit@lib/junit-4.12.jar
+// ERROR: Cannot access class 'java.lang.Class'. Check your module classpath for missing or conflicting dependencies
+// ERROR: This annotation is not applicable to target 'member function'
+import org.junit.Test
+
+class A {
+    @Test fun <caret>testTwoPlusTwoEqualsFour() {}
+}
+
+fun test() {
+    A().testTwoPlusTwoEqualsFour()
+}

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/nonFunction.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+class A {
+    val <caret>foo = 1
+}

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/nonLetters.kt_ignored

@@ -0,0 +1,12 @@
+// CONFIGURE_LIBRARY: JUnit@lib/junit-4.12.jar
+// ERROR: Cannot access class 'java.lang.Class'. Check your module classpath for missing or conflicting dependencies
+// ERROR: This annotation is not applicable to target 'member function'
+import org.junit.Test
+
+class A {
+    @Test fun <caret>`testTwo  +  Two==Four`() {}
+}
+
+fun test() {
+    A().`testTwo  +  Two==Four`()
+}

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/notAtIdentifier.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+class A {
+    <caret>fun foo() {}
+}

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/notTestFunction.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+class A {
+    fun <caret>foo() {}
+}

idea/testData/intentions/convertCamelCaseTestFunctionToSpaced/unchanged.kt_ignored

@@ -0,0 +1,10 @@
+// CONFIGURE_LIBRARY: JUnit@lib/junit-4.12.jar
+// ERROR: Cannot access class 'java.lang.Class'. Check your module classpath for missing or conflicting dependencies
+// ERROR: This annotation is not applicable to target 'member function'
+// IS_APPLICABLE: false
+
+import org.junit.Test
+
+class A {
+    @Test fun `<caret>foo bar`() {}
+}