Extend web push support

[MarkusEngelHahnSoftware]

Hi,
this adds some missing annotations for the recently added BrowserRegistrationDescriptions and registers them with the serializer. Besides that, I added some convenience methods to NotificationHubClient in accordance with the already existing ones.

Things to consider before you submit the PR:

• Are tests passing locally?
• Are the files formatted correctly?
• Did you add unit tests?
• Did you test your change with either the sample apps that are included in the repository or with a blank app that uses your change?

Related PRs or issues

#314

Misc

"CreateBrowserTemplateRegistrationAsync" methods are currently not added it INotificationHubClient.

[MarkusEngelHahnSoftware]

@microsoft-github-policy-service agree company="Hahn Softwareentwicklung GmbH"

[timvandesteeg]

Can someone please review this PR?

[lomagdal2]

lgtm

[PaulLoganCamden]

lgtm

Hey lomagdal2, I'm nervously excited about you getting this one over the finish line. 😬😃

Do you have any idea when you will have the time to wrap this one up?

Many, many thanks,

Paul.

[PaulLoganCamden]

Hey @lomagdal2 , any chance of a Friday treat? 🍦

[curlybapchap]

😴🥺😩 @lomagdal2

[PaulLoganCamden]

😴🥺😩🧟‍♂️💀 @lomagdal2

[curlybapchap]

@lomagdal2

[PaulLoganCamden]

Numbers say it all....

[curlybapchap]

FFS!!!!

Press the flippin button 🤬

[stasnovogursky]

Pleeeeeeease aprove!

[sreehari-ms]

Hello folks! Apologies for the late reply. We are currently working on enhancing our core security for ANH and have added this task into our backlog. We will keep you posted once we review and merge the code. Thanks for using ANH for your notification needs.

[SpikeViper]

The absolute glacial pace of such a core package being updated makes me question using Azure for my project. Microsoft's own cloud service doesn't have an updated SDK in their own language? Come on.