Add AQL pagination and dynamic include fields to avoid query timeouts

[christianwaldmann]

Motivation

AQL queries can timeout out on large repositories. Two causes:

1. Fetching all results in one AQL request can hit the query timeout threshold on large repos (default 900 s). Paginating in batches keeps each query within it.
2. Always fetching property and stat triggers unnecessary SQL joins even when the active rules don't need those fields, inflating every query

What does this PR do?

• Add optional page_size parameter to fetch artifacts in pages instead of a single request. When not set, behavior is unchanged
• Add aql_add_include() hook so each rule declares only the AQL fields it actually needs, replacing the hardcoded .include("*", "property", "stat") on every query

Usage

policies:
  - name: Remove old files
    page_size: 5000
    rules:
      - rule: ...

[christianwaldmann]

hi @allburov, can you have a look at this PR please and include it in a new release?