GetSectionHeader: bound the section-name read loop (matches GetSymbol fix from #32)

[nurdymuny]

Summary

Adds the i < sizeof(VerboseStr) bound to the section-name fgetc loop in
GetSectionHeader() and appends an explicit NUL terminator after the loop.

This matches the fix that was applied to the identical loop in GetSymbol()
in commit 75844867 (Fix #32, May 2020) — that pass touched the symbol-name
loop but missed the sibling section-name loop one screen up.

Without this bound, an ELF input whose section header string table contains
a string of 60+ non-NUL bytes overflows the fixed 60-byte stack buffer
VerboseStr[60].

Diff

-        while ((VerboseStr[i] = fgetc(SrcFileDesc)) != '\0')
+        while ((i < sizeof(VerboseStr)) && ((VerboseStr[i] = fgetc(SrcFileDesc)) != '\0'))
         {
             i++;
         }
+        VerboseStr[i % sizeof(VerboseStr)] = '\0'; /* nul-terminate; see the GetSymbol() loop for the same fix shape */

Tests

• Verified by inspection against the GetSymbol() loop at line 1971 which
  uses the same buffer and same fix shape.
• Static analysis baseline (CodeQL / Cppcheck) in the existing CI should
  remain clean; this change closes one finding rather than introducing one.

Linked

Closes #163.