Bug: Closed caption keyvalues may not parse correctly in certain edge cases and spew garbage

[pivotman319-owo]

Describe the bug

Not exclusive to Strata engine branch. See ValveSoftware/Source-1-Games#6770

raw failing closecaption kv in subtitles_english.dat, as of latest P2CE staging build:

same failing closecaption kv in raw datafile (subtitles_english.txt):

        "glados.testchambermisc23"    "<clr:163,193,173><B>GLaDOS:<B> You know how I'm going to live forever, but you're going to be dead in sixty years? Well, I've been working on a belated birthday present for you. Well, more of a belated birthday medical procedure. Well, <I>technically,<I> it's a medical experiment. What's important is, it's a present!"

To Reproduce

1. closecaption 1; cc_subtitles 1 in console
2. map sp_a2_laser_relays
3. solve the test chamber; alternatively, cc_emit glados.testchambermisc23 in console

Issue Map

Not Applicable

Expected Behavior

The CC kv value should be parsed and displayed correctly

Operating System

Windows 11 24H2 Dev Channel - 10.0.26100.2415 (ge_release_svc_betaflt_im.241116-1208) amd64fre