Multiselect closes when user marks search filter text and releases mouse outside of Multiselect area

[alkn87]

Expected behavior:

Firefox has the right behavior:

1. User opens the Multiselect
2. Enters some string into the search filter field.
3. User wants to copy the input string by marking it with the mouse pointer.
4. User goes from right to the left while holding the left mouse button to mark the text.
5. User accidentally leaves the Multiselect area and releases left mouse button.
6. Multiselect is still opened after release of the left mouse button and the text of the search filter is marked and ready for copy&paste.

Wrong behavior

Chrome has the wrong behavior:

1. User opens the Multiselect
2. Enters some string into the search filter field.
3. User wants to copy the input string by marking it with the mouse pointer.
4. User goes from right to the left while holding the left mouse button to mark the text.
5. User accidentally leaves the Multiselect area and releases left mouse button.
6. Multiselect is closed because Chrome triggers the click event based on where the mouseUp event happens.

Fix

I opened a pull request #507. By using pointer event instead of click event, this can be fixed for Firefox and Chrome.

[alkn87]

closed initial PR and created new PR #575