spread null agent object when parsing frames

[interim17]

Introduced a bug when I merged this PR.

Not all agents rendering in viewport on load.

Source of bug: I created NULL_AGENT constant to stay DRY but ended up with pass-by-reference issues

Fix: using spread operator seems to be a quick fix.

Not sure how I missed this initially or if something changed in viewer or octopus, it seemed to be working well before, sorry.

[github-actions[bot]]

jest coverage report 🧪

Total coverage

Status	Category	Percentage	Covered / Total
🔴	Statements	40.98%	2041/4980
🔴	Branches	43.21%	838/1939
🔴	Functions	37.05%	418/1128
🔴	Lines	41.2%	1954/4742

Status of coverage: 🟢 - ok, 🟡 - slightly more than threshold, 🔴 - under the threshold

[interim17]

Referenceeeeess!

（＞_＜）