perf(mapping): gate pose graph trajectory publishing

[junlinp]

Summary

• gate pose graph trajectory publishing on actual global refinement
• publish final pose graph trajectory once during map save

Testing

• not run; small control-flow change only

[github-actions]

cloc	github.com/AlDanial/cloc v 2.04 T=0.18 s (232.1 files/s, 36688.3 lines/s)

Language	files	blank	comment	code
Python	13	671	314	3740
Markdown	4	155	6	426
C++	4	60	38	409
Bourne Shell	15	41	9	272
Dockerfile	1	31	32	204
JSON	2	8	0	58
TOML	1	4	0	58
make	1	18	15	49
CMake	1	4	0	17
--------	--------	--------	--------	--------
SUM:	42	992	414	5233