Use camel-case in FirFunctionCallOrigin

Also componentCall is operator call

compiler/testData/diagnostics/tests/modifiers/operatorInfix/Simple.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER, -EXTENSION_SHADOWED_BY_MEMBER
 
 open class Example {
@@ -42,4 +43,4 @@ fun test() {
 
 fun consumeInt(i: Int) {}
 fun consumeString(s: String) {}
-fun consumeExample2(e: Example2) {}
+fun consumeExample2(e: Example2) {}