Add intention to replace snake-case test function name with a space-separated

#KT-27143 Fixed

idea/testData/intentions/convertSnakeCaseTestFunctionToSpaced/camel.kt

@@ -0,0 +1,8 @@
+// CONFIGURE_LIBRARY: JUnit@lib/junit-4.12.jar
+// IS_APPLICABLE: false
+
+import org.junit.Test
+
+class A {
+    @Test fun <caret>testTwoPlusTwoEqualsFour() {}
+}