feat: append chunk numbering to multi-part messages

[WB3IHY]

When a response is split across multiple chunks, users have no way to know
if they missed a part or how many parts to expect.

This change appends a (x/n) counter to the end of each chunk when there
are multiple chunks, e.g.:

Today's news... (1/3)
Article two... (2/3)
Article three... (3/3)

Single-chunk messages are unaffected.

Also fixes the throttle logic which was using list.index(m) — this broke
when m was modified with the suffix appended, as the modified string no
longer existed in the original list. Replaced with enumerate() throughout
the send loop for consistency.

[SpudGunMan]

I have not added this as it's perhaps only good in the news and file area (need the space for games)

It's also why I haven't patched for subject heading yet, also got sidetracked 8)

[WB3IHY]

I have not added this as it's perhaps only good in the news and file area (need the space for games)

It's also why I haven't patched for subject heading yet, also got sidetracked 8)

That's a good point. That wouldn't really be good for game responses. Failed to consider that.

Maybe a middle ground...something like chunkNumbering = True in config.ini that defaults to off, letting operators who run news/BBS-heavy bots enable it while game-focused ones leave it off.

Or I might be able to change it so that ONLY the news/file area uses the chunking. I'll look into that.

[WB3IHY]

I looked into limiting it to just the news/file area but it would require either duplicating the chunker or pre-chunking before the send path, both of which felt too hacky. The config option still seems like the cleanest approach — happy to implement it if you're interested.

[SpudGunMan]

didn't forget about this