[v0.44.x] Prep to release 0.44.3: Rename the VerifySignature Transaction Extension to VerifyMultiSignature to align with Polkadot#2195

jsdw merged 3 commits intov0.44.xparitytech/subxt:v0.44.xfrom

v0.44.x-VerifyMultiSignatureparitytech/subxt:v0.44.x-VerifyMultiSignatureCopy head branch name to clipboard