[Feature Request] Add custom extra url query values for `OtpUri` class

Some authenticator apps (i.e. Microsoft Authenticator) supports some non-standard uri query values for extra informations, such as `image` (which used to set the URL for display logo image), and so on.

Could you please consider to add an `ExtraQueryValues` dictionary into the `OtpUri` class and use it to append any extra url query values when invoking the `ToUrl` method? Although it can be done by manually update the generated string using 3rd string URI handling methods, it will be much better if this feature is integrated.

Many thanks!

Start by locating the OtpUri class and its ToUrl method, then inspect how the current URI query values are assembled. Add support for the requested ExtraQueryValues dictionary so custom values are appended when ToUrl is invoked, and verify that existing URL generation remains intact.

Written by the indexing model from the issue text.