input 'blur' handler clears suggestions too often

The 'blur' event handler for `this._input` is not appropriate for all user actions when interacting with the suggestions-related nodes.

`this.clear()` is being called, when it should not be, if the user tries to interact with the suggestions scrollbar or clicks on another non-suggestion item (such as a suggestion provider header).

See more here:
https://github.com/Esri/esri-leaflet-geocoder/blob/298916c6e8983ebac1a1750f80e264d2266b1928/src/Controls/Geosearch.js#L287-L291

Start in src/Controls/Geosearch.js at lines 287–291 and inspect the input blur handler and the suggestions-related nodes it interacts with. Reproduce interactions with the suggestions scrollbar and a non-suggestion item such as a provider header. Done means this handler no longer clears suggestions for those interactions while preserving the intended clearing behavior for other blur cases.

Written by the indexing model from the issue text.