POC: Provide server function to switch fallback music folder dynamically during play-out

Currently the fallback music folder is statically configured.

Motivation

By providing a server function to set the fallback music folder, the programme can adapt to different music pool folders during air-time.

Proposal

The audio store is extended with a audio/pool folder, containing any amount of music pools as sub-folders.

Provide a proof-of-concept for a server function set_fallback_pool(pool: String). By providing an existing folder passed in pool, the fallback music is switching to that music pool dynamically. Ideally the switch happens, after any currently playing track finished (compare track sensitivity).

If the pool variable is not set, does not point to a valid directory, or contains an empty string, the standard fallback folder is used instead.

changed milestone to %1.0-alpha6 — Wondrous Whale

added discuss label

changed the description

mentioned in issue aura#176 (closed)

assigned to @Loxbie

changed milestone to %1.0-alpha8

In todays planning meeting @Loxbie suggested to share some ideas on implementation.

unassigned @Loxbie

added Radio Helsinki label

changed milestone to %1.1