refactor CJumpNode to use SCP_vector#7432

Goober5000 wants to merge 2 commits intoscp-fs2open:masterscp-fs2open/fs2open.github.com:masterfrom

Goober5000:claude/CJumpNode_vectorGoober5000/fs2open.github.com:claude/CJumpNode_vectorCopy head branch name to clipboard