Add indicator for artifact tiers (different colours or display element)

[rdw-software]

As requested on Curse - link

I've been planning on adding it to the tooltip for a while, which is pretty straight-forward. I didn't like how it looked, though, and so I removed it. It also isn't as immediately visible (requires hovering / reading text) as adding different bar colours or new display elements.

Random ideas:

• Adding different bar colours for each tier (user suggestion). Might be confusing, and is prone to getting messy? Also would require changing the colours for banked/inBagsAP - or would it?
• Adding a border around the bars (colouring the inset area, basically). This is easier, but has the same issues - it could, however indicate maxed artifacts via glow effect?
• Adding a new display element - text would be visible but boring, other ways could work but need to fit with the rest of the display so as to not look odd
• Adding only the tooltip text. Simple. Not quite good enough?
• Adding a number or an icon (Concordance for tier 2?) somewhere, either as a separate element that can be toggled, or next to / on the bar?

Other ideas welcome :P