[cms] ui/ux improvements: my invoices / domain invoices views and filtering

[ta-lind]

Figma: https://www.figma.com/file/RuzhkKo9fUjKQLqGbUPjHl/decred-piui-cms?node-id=276%3A346

• All filtering options are condensed into 2 filter dropdowns
• First dropdown contains status checkboxes, with a default selection on All Invoices
• Second dropdown contains timeframes with a default selection on "last 3 months"
• The timeframe dropdown contains two parts, first section showing 3 premade choices of 3 - 6 - 12 months, second section replacing the current calendar type month picker to a simpler range dropdown
• For domain invoices, the "search by user" filter is positioned within the filters group
• New invoice button remains in the same known place, and is no longer surrounded by any clutter

Re: @MariaPleshkova

[xaur]

One thing about filters I would like to retain and possibly enhance is user's awareness that he is looking at filtered data.

In the past, we had cases where reviewing and paying of a few invoices was missed because the view was filtered and it was not immediately obvious (#2265). I would like the UI to help reviewers/admins never run into this situation again.

Perhaps an extra "reset filters" link/button wouldn't hurt. When clicked, it would put the filters into the least restrictive mode.