Add image format feature flags

[TheRedDeveloper]

Historically, macroquad forced png and tga support by default, with no clean way to opt into other formats or strip dependencies for ultra-lean builds.

This PR cleans up image format management by pulling out format flags into bundled features:

• image-standard (Default): Keeps existing png and tga support, and adds jpeg since it's universally expected.
• image-extended: A single opt-in flag that unlocks all remaining formats supported by the image crate (webp, gif, bmp, etc.) without cluttering the crate's top-level feature list.
• Exposes granular overrides (png, tga, jpeg) for developers who want to turn off default features and build a minimalist binary.

Changes

• Swapped image dependency to default-features = false.
• Added bundles and format-specific feature flags to Cargo.toml.