Prepare azcore v1.2.0 for release
# Release History
-## 1.2.0 (Unreleased)
+## 1.2.0 (2022-11-03)
### Features Added
* Added `ClientOptions.APIVersion` field, which overrides the default version a client
* Added package `tracing` that contains the building blocks for distributed tracing.
* Added field `TracingProvider` to type `policy.ClientOptions` that will be used to set the per-client tracing implementation.
-### Breaking Changes
-
### Bugs Fixed
* Fixed an issue in `runtime.SetMultipartFormData` to properly handle slices of `io.ReadSeekCloser`.
* Fixed the MaxRetryDelay default to be 60s.
