chore(react-tag-picker): removes freeform prop

[bsunderhus]

Previous Behavior

New Behavior

1. removes freeform prop
2. removes freeform related story

Related Issue(s)

• Fixes #

[fabricteam]

📊 Bundle size report

Package & Exports	Baseline (minified/GZIP)	PR	Change
react-tag-picker-preview @fluentui/react-tag-picker-preview - package	188.719 kB 55.819 kB	188.644 kB 55.793 kB	-75 B -26 B

_{🤖 This report was generated against de1ebdc8c44ac61696ace95998503817f9e4bfca}

[codesandbox-ci[bot]]

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[fabricteam]

🕵 fluentuiv9 No visual regressions between this PR and main

[bsunderhus]

@pradeept95, just to keep you updated. The freeform property will cease to exist