Select what firmware to download

Nobody has claimed this yet.

**Is your feature request related to a problem? Please describe.**

Currently, there's only one firmware that can be downloaded to the yellow programmable brick (the RCX). The user may blindly download the firmware without knowing what it was specifically. - Which is probably OK für 95% of the user base.

FYI: It's [firm0328.lgo](https://github.com/maehw/WebPBrick/blob/main/firmware/official/firm0328.lgo), i.e. LEGO's official firmware version 3.28.

There's other firmware available, see https://pbrick.info/index.html-p=74.html
Not only other official versions (3.09 and 3.32) but also from Dick Swan and alternative firmwares to be used with leJOS, pbFORTH and ~legOS~ BrickOS. Probably even others - if we can still find them in the WWW of this MINDSTORMS legacy.

**Describe the solution you'd like**

I'd like to have a selection dialog for the firmware. LEGO's 3.32 official firmware should probably the default so that no background knowledge is required. Choosing another firmware could be an advanced feature which is not directly visible ("expert mode") so that user's can't to something "wrong" (unintended).

**Describe alternatives you've considered**

Make the firmware files available and let the very advanced user use their web browser development console, add breakpoints to the JavaScript code and manually select the correct firmware from their. Doesn't feel very user-friendly though...

**Additional context**

Different firmwares are used for different RCX hardware revisions - or different alternative programming languages and their environments (e.g. pbFORTH, BrickOS, etc).

Start by reading the existing firmware download flow and the firmware/official/firm0328.lgo asset; the issue does not name an implementation file. Done means users can choose among available firmware files, LEGO 3.32 is the default, and advanced choices are safely exposed without requiring browser developer tools.

Written by the indexing model from the issue text.