Updated Key Vault libraries versions, CHANGELOGs and READMEs for February release.#19199

Merged

vcolin7 merged 3 commits intoAzure:release/keyvault-sdkfrom

vcolin7:update-keyvault-patch-release-february-2021

Feb 12, 2021

Commits on Feb 11, 2021

Updated Key Vault libraries versions all around. Updated CHANGELOGs and READMEs.
vcolin7
committed

Commits on Feb 12, 2021

Made changes that were missing from the latest merge from master.
vcolin7
committed
Added @ServiceMethod annotations to Key Vault clients for long running operations to follow checkstyle rules.
vcolin7
committed