Give box/footprint/polygon filters unique private node names

[rafal-gorecki]

Fixes #214.

box_filter, footprint_filter and polygon_filter each spin up their own
internal node (for TF, and for polygon_filter also pub/sub/param callbacks).
That internal node used a fixed name, so a process-wide bare
-r __node:=<name> remap (e.g. Node(name="laser_filter") in a launch file)
silently renames it too, colliding with the parent filter-chain node and
producing Publisher already registered for node name: 'laser_filter',
exactly as reported here and in #214 (comment).

Each internal node now gets a name unique to the filter instance, pinned via
its own local -r __node:=<name> argument — that survives a process-wide
bare remap since node-specific rules take precedence over the wildcard one.

This follows the same approach @jonbinney used in #248 for box_filter/
polygon_filter (opened against #231), and extends it to footprint_filter,
which #248 doesn't cover but is affected by the same root cause.

Tested against the exact repro from the issue (scan_to_scan_filter_chain,
--remap __node:=laser_filter, box_filter via params file): the
"Publisher already registered" warning and the node-name collision are
gone, and the box filter's internal node keeps a unique name in
ros2 node list.

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[rafal-gorecki]

A note on why this also drops rclcpp_lifecycle::LifecycleNode in favor of a plain rclcpp::Node for the private per-filter node (box/footprint/polygon):

These classes never actually engage the lifecycle state machine — no on_configure/on_activate overrides, and nothing anywhere in the codebase calls trigger_transition() on them. configure() here is just filters::FilterBase's own interface method, unrelated to the lifecycle callback of the same name.

Despite that, the resulting node still advertises itself as a fully manageable lifecycle node (~/change_state, ~/get_state, ~/transition_event — confirmed via ros2 lifecycle nodes). Since nothing ever spins its executor, any real interaction with those services just hangs forever (confirmed: ros2 lifecycle get <node> never returns). So today it's a node that looks lifecycle-managed to any tooling that discovers it that way, but isn't — pure surface area for zero benefit. A plain rclcpp::Node gives these filters exactly what they use (logger, clock, pub/sub, param callback) without that trap, and matches the approach @jonbinney already took in #248 for box_filter/polygon_filter.

[rafal-gorecki]

@jonbinney please review