[Composer] Bump guzzlehttp/guzzle to version 7 to suppress deprecation notices

- Bump divineomega/password_exposed to version 3 to remove dependency on Guzzle version 6
- Add new ICanHandleHttpResponses->getBodyString method to solve inheritance mismatch with GuzzleHttp\Psr7\ResponseInterface->getBody return type

src/Network/HTTPClient/Capability/ICanHandleHttpResponses.php

@@ -97,10 +97,9 @@ interface ICanHandleHttpResponses
 	/**
 	 * Getter for body
 	 *
-	 * @see MessageInterface::getBody()
 	 * @return string
 	 */
-	public function getBody();
+	public function getBodyString();
 
 	/**
 	 * @return boolean

src/Network/HTTPClient/Client/HttpClient.php

@@ -271,7 +271,7 @@ class HttpClient implements ICanSendHttpRequests
 	{
 		$ret = $this->fetchFull($url, $accept_content, $timeout, $cookiejar);
 
-		return $ret->getBody();
+		return $ret->getBodyString();
 	}
 
 	/**

src/Network/HTTPClient/Response/CurlResult.php

@@ -330,7 +330,7 @@ class CurlResult implements ICanHandleHttpResponses
 	}
 
 	/** {@inheritDoc} */
-	public function getBody(): string
+	public function getBodyString(): string
 	{
 		return $this->body;
 	}

src/Network/HTTPClient/Response/GuzzleResponse.php

@@ -163,8 +163,7 @@ class GuzzleResponse extends Response implements ICanHandleHttpResponses, Respon
 		return $this->isTimeout;
 	}
 
-	/// @todo - fix mismatching use of "getBody()" as string here and parent "getBody()" as streaminterface
-	public function getBody(): string
+	public function getBodyString(): string
 	{
 		return (string) parent::getBody();
 	}