svg widgets: normalize fills + tidy components

[rsek]

adjusts SVG widgets (rank pips + clocks) to make them more flexible when re-styled (whether internally or via a user stylesheet).

• stroke and fill are now currentColor, so they'll be whatever the css color is for that element
• hover, selected, and active fills are now changed by altering the fill-opacity attribute

[rsek]

• housekeeping: added {{themeClass}} to hbs templates that were still using a static theme-ironsworn
• hover "preview" effect for rank pips and clock wedges is now pure CSS, instead of adding/removing classes
• pip shape now changes with theme. starforged uses its thematic hexes, while classic ironsworn uses circles (less strongly established than hex pips are for SF, but more "on theme" given that ironsworn uses circles in almost every place SF uses a hex)

[ben]

Needs a rebase after merging #466