lint: enable mypy checking for missing imports

Achieve this by adding some ignore, and making data/ importable.

Co-authored-by: João Barbosa <joao.paulo.barbosa@gmail.com>

test/functional/combine_logs.py

@@ -188,7 +188,7 @@ def print_logs_plain(log_events, colors):
 def print_logs_html(log_events):
     """Renders the iterator of log events into html."""
     try:
-        import jinja2
+        import jinja2 #type:ignore
     except ImportError:
         print("jinja2 not found. Try `pip install jinja2`")
         sys.exit(1)