[TASK] Implement WorkspaceAwareRecordService in PageService

This change:

* Implements WorkspaceAwareRecordService as replacement for current workspace implementation in Service.
* Removes redundant code no longer required for workspace operation.
* Cleans up class inclusions FQN -> short name.
* Removes a try/catch that would never be activated.
[TASK] Implement WorkspacesAwareRecordService in AbstractPageController
[TASK] Introduce constant for raw template dok type
[BUGFIX] Infinite loop when reading page rootline in workspace mode
[BUGFIX] Use original record as emulated parent for versioned records

This makes inheritance resolving in PageService include the original record as an emulated first parent record in the root line of a record, if said record is a versioned record. The effect propagates all the way through the root line, resolving the original record's parent values for each record in the root line.
Merge pull request #185 from NamelessCoder/workspaceservice

[TASK] Implement WorkspaceAwareRecordService in PageService
[BUGFIX] Analyse root line to find both main and sub template

This change ensures that when resolving the page templates, the PageService will not stop until both a main and sub template seletion value is resolved.

Close: #177
[TASK] Consistent naming
Merge pull request #187 from bjo3rnf/naming

[TASK] Consistent naming
[TASK] Further simplify page template resolving loop
[TASK] Add a break statement when sub template is resolved
[BUGFIX] Inherited sub template not used as active template
[TASK] Remove now redundant PageLayoutView override
[TASK] Update build PackageStates.php file
[FEATURE] Implement BackendLayoutProvider for 6.2+

**Note: after this, if you are on 6.2 you must select Fluidpages as "backend layout, this page" and "backend layout, subpages" value to use your template's Grid again**.

Legacy class override remains in place for support on 6.1 but can be removed when minimum requirements change.