Add CI step for handlebar templates

[rullzer]

For the stricter CSP some handlebar templates are moved to precompiled ones.

We should have a CI step to ensure this is all up to date.

ref:

• Compile filesummary handlebars #11410
• Compile handlebars template for AuthTokenView #11412
• Compile contactmenu handlebars templates #11414

[nextcloud-bot]

GitMate.io thinks possibly related issues are #10128 (Add locale to templates), #10142 (Add template renderas empty), #11412 (Compile handlebars template for AuthTokenView), #6553 (Add public page template for apps), and #11167 (occ db:add-missing-indices - Exact steps to resolve?).