fix(completion/#2583): Handle replace range after cursor

[bryphe]

Issue: Some completion providers, like TabNine, will give a replace range past the cursor, as well.

For example, in the completion case (where | is the cursor)
app.get('/|')

Selecting a completion like ', (req, res) => { would result in an extra ' at the end of the completion.

Defect: We weren't utilizing the 'end' part of the insert / replace range

Fix: Use the end column of the insert/replace range to decide how many characters after the cursor to delete.

Related #2583