fix(ui5-multi-combobox): prefilter selected items on n more click

[MapTo0]

FIXES: #3639, #3640, #3761, #3762

[niyap]

Open the test page on mobile device and check the first sample. Open the N-more popover, deselect an item via its checkbox, press the filter selected items button in order to make visible all suggestions, then press it again - the unselected item is still visible in the selected items. It should be removed, when filtered again.

[niyap]

Open the test page on mobile. Check the second sample, where there are predefined value. If you press the N-more indicator, the predefined value is forwarded to the dialog's input and the items are filtered. On the other hand, if you tap over the predefined value, in the input field or the arrow down icon, the behaviour is different - the value is not forwarded to the inner input, the items are not filtered as well as, when the dialog is closed, the predefined value is cleared.
Another issue found: For example check the first sample in the test page on mobile device. Open the dialog via the icon or via tap in the inout field. Selected all the items, press Ok and close the dialog. Then open the dialog again, no matter how. You can notice how all the items are selected and the filter button is disabled, deselect an item via its checkbox - the filter button is still disabled, which I think that is not correct because in that moment, the filtered items are different from the list with all the items.

[niyap]

When you try to delete a token via its clear icon, the dialog is always open, where the item is already deselected and no matter pressing cancel or ok button, it is deleted. In UI5 it is immediately deleted without opening the dialog.

Also, check the first sample of the test page on mobile. Tap over the 1more, tap over the filter button in order to see all suggestion, select the unselected one and press OK button. Then tap over the 2more, when the dialog is open deselect one item then tap over the filter button in order to see just the selected ones - the items are not filtered, no matter how many times you tap over the filter button all suggestions are presented both when you select to visualised all the items and just the filtered one.

[niyap]

One last thing, when we have MultiComboBox with allowCustomValues set to true. On mobile, if the value is changed from the input within the dialog and then cancel button is pressed, the value is changed instead of cancel the changes.

[niyap]

Now, if you check the sample "Validating input and predefined value" (multicombobox with allowCustomValue set to true