[tempo] Support scalable monolith mode

[hagaibarel]

Hello,

Currently there's no way to run the tempo chart in scalable monolith mode AFAIK. While the chart supports setting the number of replicas and passing ring configurations to the various components (ingester, query etc.), there's no way to add memberlist configuration.

I think scalable monolith is a good option for folks wanting to add some scale to tempo without going the distributed path (which adds a lot more complexity).

Willing to work on it if it's something that you'd be interested to support