[Feature Request] An ability to enter the amount of RAM in both MB and GB

[La1eon]

Currently this launcher only allows you to enter the amount of RAM in megabytes into the text box in the main launcher window, as the launcher always joins the entered value with "-Xmx" and "M" letter.

It would be nice to have e.g. a dropdown menu on the right side of the text box, which would let you select one of two options: "MB" or "GB". The selection will then direct whether the launcher should join the entered value with "M" letter (for MB), or with "G" letter (for GB), and "-Xmx".

The main purpose of this change is to let users allocate e.g. 8 GB of RAM without troubling to count 8 × 1024 = 8192.

I mean something like this: