util: introduce pointer collection helpers
util: introduce pointer collection helpers

Introduce helper templates to manage pointers of collections (e.g.
std::vector containing std::unique_ptrs).

Signed-off-by: Nico Reißmann <d8255cca0642bdc1e6f9b45da9cb618d308e389b@gmail.com>

phate/jive,phate/jive,phate/jive