fix: harden Protobuf Deserialization and Refactor Utilities (#1820)

* refactor: reorganize browser utility functions and improve buffer handling

* fix: harden protobuf deserialization and clean up code

* refactor: simplify data handling in GroupCipher and SenderKey classes

* fix: Ensure consistent Buffer hydration and remove redundant code

* refactor: update decodeAndHydrate calls to use proto types for improved type safety

src/Signal/Group/sender-chain-key.ts

@@ -9,16 +9,7 @@ export class SenderChainKey {
 
 	constructor(iteration: number, chainKey: Uint8Array | Buffer) {
 		this.iteration = iteration
-		if (Buffer.isBuffer(chainKey)) {
-			this.chainKey = chainKey
-		} else if (chainKey instanceof Uint8Array) {
-			this.chainKey = Buffer.from(chainKey)
-		} else if (chainKey && typeof chainKey === 'object') {
-			// backported from @MartinSchere (#1741)
-			this.chainKey = Buffer.from(Object.values(chainKey)) // temp fix // backported from @MartinSchere (#1741)
-		} else {
-			this.chainKey = Buffer.alloc(0)
-		}
+		this.chainKey = Buffer.from(chainKey)
 	}
 
 	public getIteration(): number {