Clean up bundle size reports and add a persistent PR comment

[Jason Morse (JasonVMo)]

Platforms Impacted

• none

Description of changes

• This updates the formatting of the bundle size report making it easier to read.
• It adds sideEffects: false to package json files making tree shaking work as expected for components
• It also should add a persistent comment to PR runs that shows the bundle size results.

[github-actions]

Bundle size report

Tree-shaken production Metro bundles. Component costs are relative to their platform shell; shell costs are absolute.

Platform	Scenario	Baseline cost	Current cost	Cost delta	Change	Gzip delta	Module delta
macos	shell	801.3 KiB	801.3 KiB	0.0 KiB	0.00%	0.0 KiB	+0
macos	components-button	261.9 KiB	46.4 KiB	-215.6 KiB	-82.29%	-51.6 KiB	-203
macos	components-catalog	263.9 KiB	263.8 KiB	-0.1 KiB	-0.05%	-0.0 KiB	-3
win32	shell	806.5 KiB	806.5 KiB	0.0 KiB	0.00%	0.0 KiB	+0
win32	components-button	262.0 KiB	46.4 KiB	-215.6 KiB	-82.28%	-51.6 KiB	-203
win32	components-catalog	264.0 KiB	263.8 KiB	-0.1 KiB	-0.05%	-0.0 KiB	-3
windows	shell	810.2 KiB	810.2 KiB	0.0 KiB	0.00%	0.0 KiB	+0
windows	components-button	261.8 KiB	46.5 KiB	-215.3 KiB	-82.25%	-51.6 KiB	-203
windows	components-catalog	263.8 KiB	263.6 KiB	-0.1 KiB	-0.05%	-0.1 KiB	-3

The job is advisory: size changes are reported but do not fail the pull request. Bundle or analysis errors still fail.

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View bundle-size workflow run