Ad-hoc fix in SDC CSV blocks loading

A bug was introduced during one of the latest SDC API changes caused by wrong understanding of update blocks loading API. The problem is updates queued for loading within updates list are signed with begin of the validity block while actual loading should accept validity ID for which particular update objec gets realized (loaded). This commit introduces additional argument to loader::load() implementation that is set to particular validity key (ID) for which load is performed. This arg gets forwarded through the single public API change, not used by p348reco (so p348reco is not affected at all).

Additionally, commit introduces fix for wrong std::remove_if() usage for per-part specification (not an issue currently).