fix: fx dialog positioning

[DSCaskey]

This PR fixes the positioning of the fx dialog. It now positions correctly according to the settings in the Preferences. For some reason having the resize() and a call to the position code inside the overriding showEvent() was causing unpredicatable placement of the dialog.

closes issue #1224

[what-the-diff]

🌟 Pull Request Overview 🌟

Here's what this fantastic update will bring to our app. Get ready for an even smoother user experience! 🎉

• Tailor-Made Dialog Size 📏
  We've included an awesome feature to automatically resize the dialog box based on your last saved size whenever it's launched. It's like your software has memory! 💽

• Remembering Your Favorites 📍
  Now, the dialog box can appear exactly where you'd prefer - the software will remember the spot you like the most! Less dragging around, more working efficiently. 🚀

• Cleaner Workflow 🧹
  We've wiped away some redundant resize logic in the background. Such a simple, clean, streamlined process benefits us all! 🕹️

• Ditch the Extra Check ☑️
  We've gotten rid of the isInitialized flag check. Now, the dialog box will apply the size setting every time, no second guessing required. Simplification for the win! 🎁

• Enhanced Resize Control 🕹️
  The dialog box now includes a more intuitive resize control - a size grip. This means better control and a finer-tuned experience for you! 🎈

So, get ready for these wonderful improvements coming in. We're working hard to make your experience smoother and more tailored for you! After all, it's all about you. Sit back, relax, and enjoy the wonders of technology, where every update is a step towards a better future. 🌈