provide a third option to filterText to select other modifiers

Provide an option to switch between case sensitive or case-insensitive search.

usage:

sensitive:

```
filterText: 'displayName: filterText:'
```

insensitive:

```
filterText: 'displayName: filterText: i'
```

the default is as before (insensitive)

```
filterText: 'displayName: filterText'
```