Content Focus within Editor Card

[nelsonni]

To enable #77 for Editor cards, an extension to the current Editor class is required in order to cause the code content within an Editor card to scroll to specific line and add highlighting to that line. This method should take into account scroll bounds for beginning and end of files (i.e. so that we don't scroll off the edge of a file).

[nelsonni]

This issue was originally drafted when Editor was a plain TypeScript Class, which inherited from an abstract template Card class. However, after refactoring the core to use React/Redux in #93, this issue can quickly be resolved through the use of forwardRef and ref objects being bubbled up from the AceEditor component (as described in securingsincity/react-ace#356), and using the following code to update the cursor location in editor:

editor.goToLine(3);

If this feature becomes necessary, we can begin implementing the underlying code. But for now, this is a wontfix issue.