[KnorrFG]

Additions the new multi-runtime tests need, and the pin to them.

Tests: peeriot/swarm-ci branch fknorr/multi-runtime-tests. Based on
fknorr/fix-re-placement-override.

Changes

• SupervisionTiming::DEFAULT and RESTART_DEPLOY_TIMEOUT are public in
  sorg_common::supervision, so tests derive their failover timeout from the
  timing the runtimes use. RESTART_DEPLOY_TIMEOUT moves there from
  sorg-orchestration.
• test-framework:
  • DeployedCell::replicate([tags]) runs myrmic replicate <sri> --tag ....
    It takes an array that must not be empty, checked at compile time: without
    tags the command only shows the cell's entry.
  • Swarm::scope_holder(&scope) asks the db which runtime holds a scope. A
    cell's data has exactly one holder until it is replicated, and that need
    not be the cell's host. Needs db-client's replica feature.
  • DebugListener::buffered_entries() returns the entries the debug stream
    has printed so far, without waiting.
• .ci/tests.ref pins the swarm-ci branch.