MQTT Client ID should be part of ClientOptions

[mechatheo]

Hello,

I noticed the clientId is a readonly property of the Client interface. However, very often the client id is used as an active part of the communication, e.g. for security reasons a filter is implemented and a specific client id must be set in a given network.
There is a comment saying that the id is only used for logging, which is not the case, as can be seen here:

vda-5050-lib.js/src/common/client.ts

Line 1062 in 907ff69

clientId: this.clientId,

So ideally I would suggest the client id should be part of ClientOptions.transport along with all other settings. At very least it should be made writable, to avoid hacks like those:

type Writable<T> = { -readonly [P in keyof T]: T[P] };
type WritableClient = Writable<Client>;

export class MyController extends AgvController {
    constructor(agvId: AgvId, clientOptions: ClientOptions, controllerOptions: AgvControllerOptions, adapterOptions: AgvAdapterOptions) {
        super(agvId, clientOptions, controllerOptions, adapterOptions);
        if ((adapterOptions as MyAdapterOptions).clientId !== undefined) {
            (this as WritableClient).clientId = (adapterOptions as MyAdapterOptions).clientId as string;
        }
    }
    ...
}

what do you think?