[BUGFIX] Avoid "this page" as candidate when resolving sub template

Fixes: #206
[TASK] Clean up look to resolve page template configuration
[TASK] Refactor and comment loop to resolve page template configuration
[TER] 3.1.2
[TASK] Set stability beta and version 3.2.0 for development
[TASK] Set minimum required Flux version to 7.2.0-beta