Modify access control for fetching all notification templates

[KizerovDmitriy]

GreenCityUBS PR

This pull request modifies the access control for the endpoint that fetches all notification templates.

Summary Of Changes 🔥

• Updated @PreAuthorize annotation to use @preAuthorizer.hasAuthority('SEE_MESSAGES_PAGE', authentication) for the GET /get-all-templates endpoint.

Issue Link

#6349

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