chore(log): Add log for image zoom click

[mxiao6]

No description provided.

[ConradJChan]

I'm not sure how useful of a viewer event this would be from an SDK perspective. Is this way preferred over using resin tags to track activity?

[mxiao6]

I'm not sure how useful of a viewer event this would be from an SDK perspective. Is this way preferred over using resin tags to track activity?

Discussed offline. Summary: I first tried adding resin tag to the imageEl which has mouseup event listener. However resin does’t work in that way. I looked into the resin source code and found the element with resin target tag must be button li etc. Therefore I decided to use event to log.

[ConradJChan]

It seems like we already have a zoom event emitted from the viewers -- could we enhance that to include an interactionType or something?

[mxiao6]

zoom event emitted from viewers doesn't get logged. Adding listener to viewer to specifically log zoom event in Preview.js adds a lot of complications to this PR. Instead, I just changed the event name to zoom for scalability and consistence.

[jstoffan]

In what way does it add complexity?

[mxiao6]

In what way does it add complexity?

So now it's a two-lines change. If we use emit('zoom'), we need to implement a zoom event handler and attach it in attachViewerListeners in Preview.js, which sounds more complex than two lines.