macOS: Use electron API to get dark tray icon for the light theme.

[manavmehta]

Context: #861

What's this PR do?
We made a change to make the tray icon look flushed and coherent for the dark theme
A corresponding dark icon would do the necessary for the light theme
Electron makes it possible by using Template Image

Screenshots?
Presently we have this

This commit makes this change

You have tested this PR on:

• macOS Catalina 10.15.2

[manavmehta]

@akashnimare if you could test it on your mac

[akashnimare]

@manavmehta -

https://cl.ly/4d37215646da

Check if electron handles this by default otherwise we need to add IPC when user updates the theme.

[manavmehta]

@akashnimare please have a look.
Electron is a beauty 😄

[akashnimare]

@manavmehta please fix merge conflicts.

[manavmehta]

@akashnimare fixed them.
Also was this comment intended to be here?

[akashnimare]

Did you update the tray image? I think it was updated in #894.

[manavmehta]

@akashnimare Afaik, #894 only updates the dock icon, not the tray icon
What this PR does: electron uses Template Image which consists of a black and an alpha channel and can adjust its appearance based on the theme

Quoting from electron docs :

The most common case is to use template images for a menu bar icon, so it can adapt to both light and dark menu bars.

So, we don't need two images and any ipc calls to change the image, electron does this by itself
I just renamed the tray image to take advantage of that and we won't need the green icon - coherence

[akashnimare]

@manavmehta fix the merge conflicts and we can merge this. As a follow-up, we should update our tray image because the white padding is clearly visible on macOS.

[manavmehta]

@akashnimare resolved.
Also, would it be good to open an issue for this? (as there is less chance of missing out on an issue if it's listed)

we should update our tray image because the white padding is clearly visible on macOS.

[kanishk98]

As a follow-up, we should update our tray image because the white padding is clearly visible on macOS.

Hmm, just going through this issue and I'm not sure I follow this. @akashnimare could you clarify what you mean by white padding?

[akashnimare]

LGTM on macOS.

[akashnimare]

Merged. Thanks, everyone!