Improve display of folder path when deeply nested

It’s a bit rudimentary to only show the current place in the hierarchy
and the parent. You lose a sense of how deep you are.

But we can’t just show the full path, because it can be arbitrarily
long. So what this commit does is show the full path, but truncates the
display of any items. Further-up than the current folder or its parent.

This also helps disambiguate between folders and templates, because
folders are always shown with the folder icon.

This probably won’t affect many teams, because we don’t anticipate a lot
of deep nesting.

app/assets/images/folder-black-bold.svg

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 21.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 26 20" style="enable-background:new 0 0 26 20;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#DEE0E2;}
+	.st1{fill:#0B0C0C;}
+</style>
+<path class="st0" d="M1.2,18.8V1.3h8.4l1.5,4h13.7v13.5H1.2z"/>
+<path class="st1" d="M8.8,2.5l0.9,2.4l0.6,1.6h13.2v11h-21v-15H8.8 M10.5,0H0v20h26V4H12L10.5,0z"/>
+</svg>

app/assets/images/folder-blue-bold-hover.svg

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 21.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 26 20" style="enable-background:new 0 0 26 20;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#DEE0E2;}
+	.st1{fill:#2B8CC4;}
+</style>
+<path class="st0" d="M1.2,18.8V1.3h8.4l1.5,4h13.7v13.5H1.2z"/>
+<path class="st1" d="M8.8,2.5l0.9,2.4l0.6,1.6h13.2v11h-21v-15H8.8 M10.5,0H0v20h26V4H12L10.5,0z"/>
+</svg>