Added various backpacks

Added:

• "[501st] AB Jumppack MED" (Acklay Medical Jetpack with 1000 space)
• "[501st] Radio Pack (Medical)" (LR Small with 1000 space)
• "[501st] MYN Radio Pack (Small)" (LR Small with mynock flip script)
• "[501st] MYN Radio Pack (Medical)" (LR Small with mynock flip script and 1000 space)
• "[501st] MYN Radio Pack (Attachment)" (LR Attachment with mynock flip script)

To test, verify the backpacks exist, can be equipped, and have the stated additions.