[bardesss]

Article text, icons and picker fixes. Stacked on #39; merge that first.

Article text

• Links resolve against the article URL, so relative and protocol-relative links can be tapped. Only http and https become links.
• Table cells are separated by a space.

Images and icons

• Lead images on http load over https. An http-only site still shows no image.
• The svg icon decoder reads at most 1 MB and fails beyond it, so the row keeps its letter tile. The wide-gamut colour filter now only starts a match at the start of a property name, so it stays linear on long input.
• Favicon URLs are parsed with OkHttp's HttpUrl, which encodes spaces and similar characters and only accepts http and https.

Picker

• Picker rows are at least 48 dp tall.

Tests: HtmlTextTest, LeadImageTest, new SvgIconsTest, FaviconTest, PickerDrawerFoldTest. Full unit tests and lint pass.

Fixes from the final review

• A mark all read no longer deletes the pending read marks it covers. It flags them as attempted, so a later unread still replaces them, and they are sent after the mark-all, also when the server rejects it.
• The release workflow stops when the tag list cannot be read, instead of tagging v0.1.0.
• A flush-only job runs five times in all, not six.
• The Sign in button looks disabled while a field is blank.
• Two tests that could fail at random are fixed: the svg icon test loads the graphics runtime before its timer starts, and a list state test waits for the list to update before restoring.