use `name="ign"` for SkyCrypt interop

[nstringham]

This PR makes a few small changes to the username input fields to make it easier for people who want to view the same profiles on SkyCrypt and on SkyLea.

• change the input type from text to search this allows browsers to suggest recent searches to the user.
• set input name to ign this is to match SkyCrypt so the browser can suggest recent SkyCrypt searches in SkyLea and vice versa.
• add enterkeyhint and aria-label to improve accesablity
• remove icons that chrome and safari place onto input[type="search"]

Screenshot on Desktop Chrome

[nstringham]

This PR also stops LastPass from thinking that the main username input is a signing field