Merge pull request #374 from anhtumai/358-add-dark-theme

Set version to 4.6.2

Support Werkzeug 3 by using a default encoding of UTF-8

enable theme for export utility

add html tags to all output html

fix test-api

remove body class

add theme arguments to README.md

remove enum because the app needs to work with python2

set data_color_mode, data_light_theme, data_dark_theme based of theme argument

add theme argument,

Set version to 4.6.1

Merge branch 'add-flask-2.1.0-support'

Normalize subpath redirects on page visit

Add Flask 2.1.0 support