Revert "src: Simplify HintState constructor"

This reverts commit 092e501db4.

This was causing a bug identified by @glacambre and @Lexi where
sometimes the html function isn't defined when returning to a page with
history back.

Personally, I think it's probably webpack or Firefox's fault: content.ts
clearly imports html-tagged-template as it's first action.

If it's not their fault then it's html-tagged-template's fault: it must
be refusing to set window.html.

src/hinting.ts

@@ -25,12 +25,16 @@ const logger = new Logger('hinting')
 /** Simple container for the state of a single frame's hints. */
 class HintState {
     public focusedHint: Hint
-    readonly hintHost = html`<div class="TridactylHintHost cleanslate">`
+    readonly hintHost = document.createElement('div')
     readonly hints: Hint[] = []
     public filter = ''
     public hintchars = ''
 
-    constructor(public filterFunc: HintFilter) {}
+    constructor(
+        public filterFunc: HintFilter,
+    ){
+        this.hintHost.classList.add("TridactylHintHost", "cleanslate")
+    }
 
     destructor() {
         // Undo any alterations of the hinted elements