dropdown_list_widget: Add 'type' attribute to reset button.
dropdown_list_widget: Add 'type' attribute to reset button.

Previously, when a user hits 'Enter' key within a input
field it incorrectly triggers the dropdown_list_widget's
reset button.

This is because the reset button had the default type attribute of
'submit' which triggers the click event binded to it. Fixed it by
explicitly defining it's type attribute to be a button.

punchagan/zulip,eeshangarg/zulip,hackerkid/zulip,rht/zulip,rht/zulip,andersk/zulip,zulip/zulip,andersk/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,rht/zulip,andersk/zulip,kou/zulip,zulip/zulip,kou/zulip,hackerkid/zulip,rht/zulip,punchagan/zulip,punchagan/zulip,eeshangarg/zulip,eeshangarg/zulip,hackerkid/zulip,punchagan/zulip,hackerkid/zulip,eeshangarg/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,zulip/zulip,rht/zulip,andersk/zulip,punchagan/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip,andersk/zulip,kou/zulip,kou/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,zulip/zulip,hackerkid/zulip