fix: MenuItem is only focused when mouse cursor is moved

[ling1726]

Currently the MenuItem uses onMouseEnter to focus - this causes a nasty side effect where the menu item is focused if the menu opens and hte cursor just happens to be on top of a menuitem.

This PR changes the logic to use onMouseMove which requires the user to explicitly move the cursor inside the menu item

Previous Behavior

New Behavior

Related Issue(s)

• Fixes #

[github-actions]

📊 Bundle size report

Package & Exports	Baseline (minified/GZIP)	PR	Change
react-components react-components: Accordion, Button, FluentProvider, Image, Menu, Popover	224.117 kB 64.843 kB	224.18 kB 64.859 kB	63 B 16 B
react-components react-components: entire library	1.169 MB 292.716 kB	1.169 MB 292.741 kB	63 B 25 B
react-menu Menu (including children components)	155.553 kB 46.863 kB	155.616 kB 46.882 kB	63 B 19 B
react-menu Menu (including selectable components)	158.535 kB 47.46 kB	158.598 kB 47.478 kB	63 B 18 B

Unchanged fixtures

Package & Exports	Size (minified/GZIP)
react-avatar Avatar	49.329 kB 15.824 kB
react-avatar AvatarGroup	20.132 kB 7.976 kB
react-avatar AvatarGroupItem	63.473 kB 20.043 kB
react-breadcrumb @fluentui/react-breadcrumb - package	114.317 kB 31.702 kB
react-components react-components: Button, FluentProvider & webLightTheme	69.236 kB 20.182 kB
react-components react-components: FluentProvider & webLightTheme	44.473 kB 14.597 kB
react-datepicker-compat DatePicker Compat	225.344 kB 63.793 kB
react-dialog Dialog (including children components)	100.513 kB 30.131 kB
react-overflow hooks only	12.808 kB 4.819 kB
react-persona Persona	56.22 kB 17.704 kB
react-popover Popover	130.32 kB 40.699 kB
react-portal-compat PortalCompatProvider	8.39 kB 2.64 kB
react-table DataGrid	161.06 kB 45.718 kB
react-table Table (Primitives only)	42.692 kB 13.862 kB
react-table Table as DataGrid	131.895 kB 36.579 kB
react-table Table (Selection only)	70.562 kB 20.007 kB
react-table Table (Sort only)	69.205 kB 19.618 kB
react-tag-picker @fluentui/react-tag-picker - package	185.734 kB 55.759 kB
react-tags InteractionTag	15.225 kB 6.165 kB
react-tags Tag	29.098 kB 9.559 kB
react-tags TagGroup	82.745 kB 24.532 kB
react-teaching-popover TeachingPopover	91.711 kB 27.921 kB
react-timepicker-compat TimePicker	108.551 kB 36.094 kB
react-tree FlatTree	147.295 kB 42.271 kB
react-tree PersonaFlatTree	148.04 kB 42.417 kB
react-tree PersonaTree	144.249 kB 41.27 kB
react-tree Tree	143.51 kB 41.149 kB

_{🤖 This report was generated against ab504b182ef3b6c7594fce9aa91948dac8332dd5}

[github-actions]

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