Fixes #2328. TextView Autocomplete triggered by cursor move.

[BDisp]

Fixes #2328 - With this PR the Autocomplete popup will only show by typing a key or the Reopen key. However it's also possible show by set the TextView.CursorPosition. But the issue is only related with cursor move and mouse button click.
@tznind please review because I don't want to broken anything. Thanks.

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[tig]

Lovely.