BS4 by default, BS5 optional

Bootstrap 4 w/ jQuery is used by default unless bs5 is enabled in
settings/ui. bs4 also now has a jellyfin-style look.

jellyfin_accounts/web.py

@@ -11,6 +11,7 @@ def page_not_found(e):
     return (
         render_template(
             "404.html",
+            bs5=config.getboolean('ui', 'bs5'),
             css_file=css_file,
             contactMessage=config["ui"]["contact_message"],
         ),
@@ -23,6 +24,7 @@ def admin():
     # return app.send_static_file('admin.html')
     return render_template(
         "admin.html",
+        bs5=config.getboolean('ui', 'bs5'),
         css_file=css_file,
         contactMessage="",
         email_enabled=config.getboolean("invite_emails", "enabled"),
@@ -32,10 +34,18 @@ def admin():
 @app.route("/<path:path>")
 def static_proxy(path):
     if "html" not in path:
+        if "admin.js" in path:
+            if config.getboolean('ui', 'bs5'):
+                bsVersion = 5
+            else:
+                bsVersion = 4
+            return render_template("admin.js",
+                                   bsVersion=bsVersion)
         return app.send_static_file(path)
     return (
         render_template(
             "404.html",
+            bs5=config.getboolean('ui', 'bs5'),
             css_file=css_file,
             contactMessage=config["ui"]["contact_message"],
         ),
@@ -53,6 +63,7 @@ def inviteProxy(path):
             email = ""
         return render_template(
             "form.html",
+            bs5=config.getboolean('ui', 'bs5'),
             css_file=css_file,
             contactMessage=config["ui"]["contact_message"],
             helpMessage=config["ui"]["help_message"],
@@ -69,6 +80,7 @@ def inviteProxy(path):
         log.debug("Attempted use of invalid invite")
         return render_template(
             "invalidCode.html",
+            bs5=config.getboolean('ui', 'bs5'),
             css_file=css_file,
             contactMessage=config["ui"]["contact_message"],
         )