Refactor buttonbar into its own component

[brianlove]

Refactor the buttonbar and its associated window resize logic into its own component.

Closes #465

[github-actions[bot]]

No need for rebasing :+1: behind_count is 0 ahead_count is 1

[github-actions[bot]]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
637	425	67%	0%	🟢

New Files

No new covered files...

Modified Files

No covered modified files...

updated for commit: a8e00d2 by action🐍

[github-actions[bot]]

JavaScript Coverage

Summary

Lines	Statements	Branches	Functions
	68.98% (456/661)	56.31% (232/412)	70.55% (139/197)

Modified Files • (68%)

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	68.98	56.31	70.55	68.84
components	64.9	54.81	64.74	64.54
ListViewButtonBar.jsx	86.04	90	100	86.04	130–132, 134–136
ListViewTable.jsx	90.83	72.89	98.36	90.72	216, 299–300, 305–308, 416, 461, 621, 642–645, 661–662, 686–687, 690, 708–711, 735, 749–754