Add clear button on small screen

From https://discuss.tryton.org/t/improve-search-filter-on-client/1093/8

assigned to @ced

added sao tryton type::feature + 1 deleted label

added 1 deleted label and removed 1 deleted label

review62431003 updated at https://codereview.tryton.org/62431003/#ps1

review50751002 updated at https://codereview.tryton.org/50751002/#ps1

review62431003 updated at https://codereview.tryton.org/62431003/#ps20001

New changeset 5b2da063eccb by Cédric Krier in branch 'default':
Add clear button for search entry and reorder buttons
https://hg.tryton.org/sao/rev/5b2da063eccb

added 1 deleted label and removed 1 deleted label

closed

New changeset 166dcb5e896d by Cédric Krier in branch 'default':
Reorder search entry buttons
https://hg.tryton.org/tryton/rev/166dcb5e896d

New changeset e289a6957201 by Cédric Krier in branch 'default':
Add clear button for search entry and reorder buttons
https://hg.tryton.org/tryton-env/rev/e289a6957201