#4119 - fix focus and for buttons and skipped elements

[Ifycode]

This pull request makes the following changes:

• Fixes Weak color contrast and issues for tab key users in the map and search area of the map page. platform#4119

Issues, observation & steps taken:

• Button elements are not focusable. Removed the outline set to none. See associated platform-client PR.
• In smaller devices, span.mode-context-trigger is skipped. Changed it to button so that focus set for buttons can work on it and also so its role is clear to assistive technology like screen reader.

Testing checklist:

• Add assets folder from platform-pattern-library containing the new changes made to the platform-client which also contains some new changes and run the project.

• Login, and use tab key to navigate the toolbar on the map page.

• Check that buttons are not skipped and in correct order.

• Check that it is obvious to user that a button is in focus.

• I certify that I ran my checklist

Fixes ushahidi/platform#4119 .

Ping @ushahidi/platform

[Ifycode]

Hi @Angamanga please discard that other PR i started with.

This is the 2nd new PR that deals with buttons (only).
Please help review.