add two missing HTML tags (fixes 4005)

nicegui/html.py

@@ -52,6 +52,7 @@ figure = _create_html_element('figure')
 footer = _create_html_element('footer')
 form = _create_html_element('form')
 h1 = _create_html_element('h1')
+header = _create_html_element('header')
 hgroup = _create_html_element('hgroup')
 hr = _create_html_element('hr')
 i = _create_html_element('i')
@@ -105,6 +106,7 @@ tfoot = _create_html_element('tfoot')
 th = _create_html_element('th')
 thead = _create_html_element('thead')
 time = _create_html_element('time')
+tr = _create_html_element('tr')
 track = _create_html_element('track')
 u = _create_html_element('u')
 ul = _create_html_element('ul')