Update gatsby to 4.8.1

• Update gatsby and packages to resolve dependency error
• Fix theme to work with new version
• Fix configs

added bug label

assigned to @drateots

npm prints security warnings. I looked through them and they don't look like affecting us (but I'm not a security expert) i.e. gatsby sites. Anyway there is no answer in google and it seems others come to the same conclusion.

approved this merge request

mentioned in merge request !18 (closed)

approved this merge request

merged