Make Autocomplete Case Insensitive

[bscan]

Currently, auto-complete appears to be case-insensitive, but it is not. This is because the vscode selector is case insensitive, but when it reloads the completion results, the navigator is case-sensitive. This causes confusing behaviors where the autocomplete will get lost. Let's move autocompletion toward entirely case-insensitive. I suspect this ticket is trickier than it sounds due to the autocompletion on arbitrary recognized objects.