Fix EZP-22225; Publishing content in a symfony command throws InactiveScopeException

https://jira.ez.no/browse/EZP-22225

When launching a CLI command with `ezpublish/console`, some pre-checks are invoked and all registered commands are being called with `isEnabled()` method. In these cases, the router is often called (e.g. to warm up route cache) and this makes the legacy kernel being *pre-booted* (closure is ready), but with the default kernel handler (`ezpKernelWeb` instead of `CLIHandler`). Indeed, the appropriate handler is only set when commands are being registered (not possible before for various reasons).

Considering this preamble, solution is quite simple (declaring 2 services as *lazy*), but needs some explanation:
* `ezpublish.signalslot.repository` - Actually the problem here is one of its dependency, `ezpublish.signalslot.signal_dispatcher` which is being built with all legacy aware slots, depending on the legacy kernel. This service is called when loading the router.
* `ezpublish_legacy.router` - Also called when loading the router.

When launching a CLI command, router can be loaded:
* By the cache warmer service (warm up route cache)
* By `router:dump-apache` command, when `isEnabled()` is invoked.

Declaring those 2 services as lazy should definitively solve this issue.