AddComponent() now throws a crash message when the comp type arg is not a component. (#76221)

## About The Pull Request
HEY! Did you know that the AddComponent() proc can complete without
throwing errors when the component type argument is actually not a type
or instance of a component? Me neither (until now), but I've recently
discovered that while working on #76219 (Make sure to merge that one
first).

Also adds early return checks to the AddElement and RemoveElement procs.

## Why It's Good For The Game
Silent bugs are awful.

## Changelog
N/A

code/datums/elements/_element.dm

@@ -53,6 +53,8 @@
 	if(QDELING(src))
 		CRASH("We just tried to add an element to a qdeleted datum, something is fucked")
 	var/datum/element/ele = SSdcs.GetElement(arguments)
+	if(!ele) // We couldn't fetch the element, likely because it was not an element.
+		return // the crash message has already been sent
 	arguments[1] = src
 	if(ele.Attach(arglist(arguments)) == ELEMENT_INCOMPATIBLE)
 		CRASH("Incompatible element [ele.type] was assigned to a [type]! args: [json_encode(args)]")
@@ -63,6 +65,8 @@
  */
 /datum/proc/_RemoveElement(list/arguments)
 	var/datum/element/ele = SSdcs.GetElement(arguments)
+	if(!ele) // We couldn't fetch the element, likely because it was not an element.
+		return // the crash message has already been sent
 	if(ele.element_flags & ELEMENT_COMPLEX_DETACH)
 		arguments[1] = src
 		ele.Detach(arglist(arguments))