Sync eng/common directory with azure-sdk-tools for PR 1772 (#14962)
Sync eng/common directory with azure-sdk-tools for PR 1772 (#14962)

* Update change log headers based on guideline update

Updates based on https://github.com/Azure/azure-sdk/pull/3103

- Renamed "Key Bugs Fixed" to "Bugs Fixed"
- Renamed "Fixed" to "Other Changes"

Added a warning in validation if at lease one of the recommended
headers aren't used.

* Update eng/common/scripts/ChangeLog-Operations.ps1

Co-authored-by: JoshLove-msft <e37f5dd36338887dcec6be47dca99afa7f719ca6@users.noreply.github.com>

Co-authored-by: Wes Haggard <d598ed404a9a39e5ca39f22624afbc827cbec5f5@microsoft.com>
Co-authored-by: Wes Haggard <bac8a89fef25efd2c81bd803dbd39614d63d50cf@users.noreply.github.com>
Co-authored-by: JoshLove-msft <e37f5dd36338887dcec6be47dca99afa7f719ca6@users.noreply.github.com>
Azure/azure-sdk-for-go,Azure/azure-sdk-for-go,Azure/azure-sdk-for-go,Azure/azure-sdk-for-go