Configuring GCS Metadata

[HaseebLUMS]

Is your feature request related to a problem? Please describe.
When storing objects in GCS, I often have to deal with setting object-level metadata, particularly the caching-related metadata. Currently, Tempo does not provide a way to do this.

Describe the solution you'd like
A config option to set metadata. If I could define metadata in the tempo config and it gets attached to all the objects that tempo stores in the GCS, that would be the ultimate solution.

Additional context
I have been benchmarking Tempo on deciding an ultimate tool for my different use cases. During the benchmarks, I wanted to configure the GCS caching behavior that is often configured using object-level metadata. Unfortunately, Tempo does not provide a way to configure any kind of Cloud Storage metadata.