Fix memory leaks with Plugin store layout

[onesounds]

What's the PR

• Decode Image Size in Theme Preview
  • Reason : if user use big size wallpaper, it will effect to flow. size decode will solve the problem.
  • I don't think it's a big problem, although the image drops to low definition.
• Use Virtualizing Panels in Plugin Store List / plugin list / ETC for memory leak
• Refactor Plugin Store UI (Changed Wrap panel from Uniform grid.)
  • Reason : in this case, item size doesn't fit with list width. Several implementations were attempted, but this condition was judged to be good because performance problems occurred and design problems were not significant.
• 'Update Label' (Green Ball) changed placement to icon's right.
  • Reason : Due to implementation problems, it could not be displayed in the upper right corner.

Test Cases

• No excessive memory leaks should occurrence with all menu.
• Wallpaper displayed on the theme menu should be displayed in low resolution. (It has to be a level that doesn't bother you.)
• Items in the plug-in store must be displayed appropriately even if you resize the window
• The menu displayed when each item is clicked must operate normally.
• Group (New, Installed....) and searches must operate normally.

[onesounds]

@taooceros 'refresh' button wrong work after merged Label PR , It seems like a simple task, but I couldn't fix it. Please add it on this pr or work on it separately. (Don't forget it!)

[jjw24]

@onesounds Are the test cases completed?

[onesounds]

@onesounds Are the test cases completed?

in my case, Yes. but not sure. simply you can test (like when you did in smooth scroll pr) memory leak issue and working plugin store buttons. if its all fine, it is mergable.

[jjw24]

With dev branch, I can consistently push the memory usage up to 330mb on average by going to Settings -> Plugin Store scroll up and down a couple times -> exit and then repeat. Doing the same with this PR I see memory usage is around 250mb on average and only hits as high as 280mb rarely for a second but then quickly drops back down to the 250mb average.

🥇 @onesounds @taooceros

[jjw24]

Installing plugins via mouse click is not working. Click on the install button then use mouse to click the install plugin result, nothing happens. Using enter works.

[onesounds]

Installing plugins via mouse click is not working. Click on the install button then use mouse to click the install plugin result, nothing happens. Using enter works.

ok. I'll check. when fix done, I'll mention you again. thanks.