v4.2.0 - general upgrade

• Eliminated multiple bugs regarding creating, saving, and searching databases.
• Faster database creation by specifying batch size based on the vector model selected, and also lower VRAM usage as a result. This was only done after extensive testing.
• Make sure that all audio and image files are displayed in the database viewer tab now and that they open the appropriate file when doubleclicked.
• Updated user guide.
• Remove certain vector models that had significantly higher compute/VRAM requirements but no greater quality than other models that require less compute/VRAM. This was only done after extensive testing.
• Other relatively minor changes.