feat: make zoomLevel/zoomFactor sync

[codebytere]

Description of Change

Convert webContents getZoomLevel and getZoomFactor to be sync methods.

cc @ckerr

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Converted zoomLevel() and zoomFactor() for webContents and <webview> to return a promise instead taking a callback.

[deepak1556]

GetZoomFactor and GetZoomLevel were originally implemented using webFrame apis, hence they had to rely on ipc and had an async api signature. It then got refactored to rely on the browser side ZoomController. These apis no longer need to be async, its better to deprecate the current signature in favor of that instead of promisification.

[deepak1556]

Is there a plan to handle the deprecations of the async signatures ?

[codebytere]

Must be merged with: electron/typescript-definitions#119

[release-clerk]

Release Notes Persisted

Converted zoomLevel() and zoomFactor() for webContents and <webview> to return a promise instead taking a callback.