Pipeline Clean-up

- [ ] Enable 1ES auto-baselining correctly in all repos and ensure it is working (see https://github.com/Azure/azure-sdk-for-rust/commit/845eceedaf719a49be8a0b52457c5887af182c1d fo the last fix in rust). Remove `featureFlags.autoBaseline` if it is set.
- [x] Disable CredScan from all jobs in the pipeline except a nightly job.
- [x] Disable Policheck from all jobs in the pipeline except for a nightly job.
- [ ] Disable ComponentGovernance from all public pipeline jobs. Enable it only for publishing drops internally and a night aggregate job.
- [ ] Add support for manually queuing the new ` - pullrequest` pipelines. Treat commits of the form `refs/pull//merge` as if they were triggered via PR.
- [ ] Clean-up eng/common sync to reduce time and dependency on manual rest api calls, instead use gh cli or other.
- [ ] Examine the nightly job pipelines, ie. Aggregate Reports to ensure they are running the compliance tools we need.
- [x] Switch to Github Actions for the PR validation in azure-sdk repo.
- [ ] Examine the performance of the new `pullrequest` pipelines to make sure we aren't wasting time.
- [ ] Clean-up any warnings related to 1ES templates or others to ensure we don't have a lot of noise in our pipelines.