Add default case to all savegame tag switches to prevent parser desync

[acato]

Summary

• Adds default: bContinue = false; break; to 19 savegame switch statements that had no default case
• Adds bContinue = false; to 3 existing default cases that only had FAssert (stripped in Release builds)
• Without this, an unrecognized tag value leaves its data bytes unconsumed, permanently misaligning the parser — a crafted savegame exploits this to inject controlled values into arbitrary game state fields

22 files touched — all *Savegame.cpp files with tag-reading switch statements.

Fixes #1230

Test plan

• Load an existing savegame — verify it loads identically to before (no false positives from the default case)
• Save and reload mid-game — verify no data loss
• In Assert build: verify no FAssert fires during normal save/load (confirms no legitimate tag hits the default)
• Confirm the fix compiles cleanly in Assert, Release, and FinalRelease targets

🤖 Generated with Claude Code