webui: configure routes — static route management page

Adds Configure > Routes page for viewing, adding, editing, and deleting
IPv4 and IPv6 static routes.  Each route row expands in-place to an edit
form; YANG field descriptions are shown as ⓘ tooltips.

Also fixes a goyang bug where inline augments inside a uses block were
never applied to the expanded tree, making it so next-hop-address and
outgoing-interface were missing from the schema — and therefore had no
tooltip text.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/webui/static/css/style.css

@@ -2122,7 +2122,7 @@ select.cfg-input {
 
 /* Editable table rows */
 .cfg-table td { padding: 0.45rem 0.75rem; vertical-align: middle; }
-.cfg-table td:last-child { width: 3rem; text-align: center; }
+.cfg-table > tbody > tr > td:last-child { width: 3rem; text-align: center; }
 /* Leading nav-chevron column for complex (drill-down) list rows */
 .yt-nav-col { width: 1.5rem; padding: 0.25rem !important; text-align: center; color: var(--fg-muted); }
 .btn-icon {

src/webui/static/img/icons/routes.svg

@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <circle cx="5" cy="12" r="2"/>
+  <circle cx="19" cy="6" r="2"/>
+  <circle cx="19" cy="18" r="2"/>
+  <line x1="7" y1="11" x2="17" y2="7"/>
+  <line x1="7" y1="13" x2="17" y2="17"/>
+</svg>