Repository is here: https://bitbucket.org/MartinRJ/storm-1911

I more or less cloned the search-function and modified the floater via xml (new file: floater_goto_line.xml) to fit for a 'go to line' floater.
Also I added a callback to prevalidate the input in the 'go to line' line-editor, so that only numbers can be entered into it.

Tested on my local PC with a modded "3.3.4-release3" version.
Open a script with at least 300 lines inside inventory, go to menu 'Edit-> go to line', enter a number less than 300 into the 'Go to' - field. Expected result: the cursor jumps to the entered line number (column 0).
Repeat the test with a script inside an object's content.