Octavia Microversion Support

Issue

• It starts to difficult to manage features in Octavia service because there only v2 and all subsequent minor versions are part of it.

• For example, the availability zone support was added in 2.14, but the client cannot manage what minor version it wants to use.

• We want to suggest to implement microversion support in Octavia API in the way Nova, Cinder, and other projects do.

• The old one task that was never started is here