Support detection of REFRESH queries

[namiyousef]

Is your feature request related to a problem? Please describe.
I tried using sqlparse to get the type of the following query:
REFRESH MATERIALIZED VIEW order_summary; but it results in UNKNOWN. Upon further exploration I see that there is no REFRESH keyword in keywords.py

Describe the solution you'd like
Addition of REGEX pattern for ability to identity such queries, or the addition of the REFRESH and MATERIALIZED keywords in keywords.py

Describe alternatives you've considered
None