fixes#11343
- solves the case where themes depends on old labs flags that are now always false, but the DB still has the feature set to true
- add concept of deprecated labs flags to the labs service
- make sure that the labs service gets used in our theme middleware
- added tests and other small fixes
no issue
- Removed deprecated 'blog' reference from frontend data. The alias (site->blog) stays till next version (v4) as it's not leaving much of technical debt but would ease the migration process for anybody still using it.
- The follow up to this is substitute of all references to `options.data.blog` with `options.data.site` in "frontend"
- Fixed test utils helper to use `site` instead of `blog`
- Removed 0.1 flag checks in {{get}} helper
- Removed user aliasing from {{get}} helper
- Removed unused translation for {{get}} helper
- Added a note to excerpt changes in metadata for future reference
- Removed page alias used in description helper. The mix of page context with post object in the metadata was only possible in v0.1
- Changed mock in ghost_head helper to use v2
- Removed unneeded test for body class helper
refs #10790
- Moved /core/apps into core/frontend
- Moved /core/server/helpers to /core/frontend/helpers along with /core/server/services/themes
- Changed helper location in overrides
- Moved /core/server/services/routing to /core/frontend/services
- Moved /core/server/services/url to /core/frontend/services
- Moved /core/server/data/meta to /core/frontend/meta
- Moved /core/server/services/rss to /core/frontend/services
- Moved /core/server/data/xml to /core/frontend/services
