WIKI-743: Slowness when checking permissions: Utils.canModifyPagePermission - Backport to feature/stabilization.

Fix description: Avoid redundant call session.save() when getting Wiki object

Conflicts:
	wiki-service/src/main/java/org/exoplatform/wiki/mow/core/api/wiki/GroupWikiContainer.java
	wiki-service/src/main/java/org/exoplatform/wiki/mow/core/api/wiki/UserWikiContainer.java