Fix stack overflow in HTML generation

[AllanBlanchard]

I found a stack overflow when running bisect on the code base of Frama-C. This PR replaces a try catch with a match exception to avoid stacking try contexts. I would probably be better to make the function tail recursive though, but I don't know when I can do it. Ok, I miss-used the [@tailcall], now it is tailrec.

[AllanBlanchard]

Ok, the CI has the same behavior as on the master branch so I guess we are OK here.

[aantron]

Thank you! This will be included in the next release.