Fix: Replace `sprintf()` calls remaining in firmware with `snprintf()`

[ALTracer]

Detailed description

• Not a feature.
• The existing minor problem is inconsistency in usage of sprintf/snprintf in firmware (target drivers).
• This PR solves it by replacing (almost as-is) the three remaining sprintf calls as highlighted by puncover and grep / the-silver-searcher with snprintf which is used much more often.

Bonus points for bounds checking, as all touched cases deal with copying a runtime-constructed pattern into a target private storage struct, which has a fixed capacity, and it's cheap to take its size [and stuff into second argument] -- not invented by me, I was just looking at other callers of snprintf. There could be stricter bounds enforced, but I won't be researching that. As measured on gcc-12 and native this drops a 64-byte siprintf shim function from current main, while retaining 104-byte sniprintf with 14 callers and _svfiprintf_r the impl proper. It may be much harder to get rid of that set of efficient newlib-nano library functions, because of e.g. existing XML builders.

I can't test against any of three touched targets.

Your checklist for this pull request

• [x] I've read the Code of Conduct
• [x] I've read the guidelines for contributing to this repository
• [x] It builds for hardware native (see Building the firmware)
• [x] It builds as BMDA (see Building the BMDA)
• [x] I've tested it to the best of my ability
• [x] My commit messages provide a useful short description of what the commits do

Closing issues