add field to request the database against the taxonomy

this field have autocompletion feature

the results are remove when the user click on the input "by strain" or "by taxonomy" instead when they have the
focus to avoid a strange behavior. when the cursor go out the window and the last widget to have the focus
is "by strain" or "by taxonomy". when the mous comme back in the window the results were cleared.

add handler on "return press" event  on widget "by name", " by taxon id", "by strain" , "by taxonomy".
to trigger the request