Added CObjError, cosmoV_throw(), pcall(), and cosmoV_printError()

Errors are now handled very differently, parser errors and VM errors are now treated the same.
When cosmoV_error is called, cosmoV_throw is also called, which formats the error object and sets the panic state.
state->error now points to the latest CObjError when state->panic is true. To get a nice formatted Objection message, use
cosmoV_printError() and pass the state->error. pcall() was added to the standard base library. When called, the first argument
passed is called with the subsequent arguments given. If the call completed successfully, `true`,`nil` is returned. However
when an error occurs during the call, `false`,`<error>` is returned. Simply print the `<error>` to retrieve the error string.

src/cstate.c

@@ -31,7 +31,9 @@ CState *cosmoV_newState() {
     state->top = state->stack;
     state->frameCount = 0;
     state->openUpvalues = NULL;
+
     state->protoObj = NULL;
+    state->error = NULL;
 
     cosmoT_initTable(state, &state->strings, 8); // init string table
     cosmoT_initTable(state, &state->globals, 8); // init global table