chore(DropdownSelectedItem): Convert to RFC

[assuncaocharles]

Pull request checklist

• Addresses an existing issue: Fixes #0000
• Include a change request file using $ yarn change

BREAKING CHANGES

Converting DropdownSelectedItem from class component to functional. Any props are not longer passed to styles function.

Related to #12237

Focus areas to test

(optional)

[msft-github-bot]

Perf Analysis

No significant results to display.

All results

Scenario	Master Ticks	PR Ticks	Iterations	Status
BaseButton	713	698	5000
Checkbox	1375	1377	5000
CheckboxBase	1125	1131	5000
CheckboxNext	1443	1394	5000
ChoiceGroup	4432	4359	5000
ComboBox	798	881	1000
CommandBar	6842	6840	1000
ContextualMenu	13276	13293	1000
DefaultButton	957	920	5000
DetailsRow	3214	3165	5000
DetailsRow (fast icons)	3121	3082	5000
DetailsRow without styles	2907	2809	5000
Dialog	1276	1276	1000
DocumentCardTitle with truncation	1534	1546	1000
Dropdown	2124	2141	5000
FocusZone	1472	1510	5000
IconButton	1493	1519	5000
Label	266	266	5000
Link	414	403	5000
LinkNext	429	402	5000
MenuButton	1280	1225	5000
Nav	2824	2805	1000
Panel	1261	1275	1000
Persona	772	747	1000
Pivot	1178	1192	1000
PrimaryButton	1114	1058	5000
SearchBox	1137	1110	5000
Slider	1356	1362	5000
Spinner	321	335	5000
SplitButton	2670	2694	5000
Stack	405	449	5000
Stack with Intrinsic children	1000	987	5000
Stack with Text children	3698	3598	5000
TagPicker	2428	2509	5000
Text	329	346	5000
TextField	1237	1239	5000
Toggle	736	774	5000
button	63	73	5000

Perf Analysis (Fluent)

Perf comparison

Status	Scenario	Fluent TPI	Fabric TPI	Ratio	Iterations	Ticks
🎯	Avatar.Fluent	0.41	0.45	0.91:1	2000	814
🦄	Button.Fluent	0.09	0.17	0.53:1	5000	461
🔧	Checkbox.Fluent	0.61	0.31	1.97:1	1000	605
🔧	Dialog.Fluent	0.3	0.17	1.76:1	5000	1482
🔧	Dropdown.Fluent	3.04	0.38	8:1	1000	3038
🔧	Icon.Fluent	0.13	0.05	2.6:1	5000	626
🦄	Image.Fluent	0.06	0.09	0.67:1	5000	318
🔧	Slider.Fluent	1.32	0.31	4.26:1	1000	1318
🔧	Text.Fluent	0.06	0.02	3:1	5000	289
🦄	Tooltip.Fluent	0.09	17.43	0.01:1	5000	437

🔧 Needs work     🎯 On target     🦄 Amazing

Perf tests with no regressions

Scenario	Current PR Ticks	Baseline Ticks	Ratio
AttachmentMinimalPerf.default	139	120	1.16:1
AlertMinimalPerf.default	272	245	1.11:1
BoxMinimalPerf.default	294	270	1.09:1
CarouselMinimalPerf.default	425	396	1.07:1
FormMinimalPerf.default	675	634	1.06:1
Image.Fluent	318	299	1.06:1
ChatWithPopoverPerf.default	485	464	1.05:1
LabelMinimalPerf.default	370	351	1.05:1
LoaderMinimalPerf.default	739	701	1.05:1
Slider.Fluent	1318	1261	1.05:1
Tooltip.Fluent	437	418	1.05:1
ReactionMinimalPerf.default	350	336	1.04:1
TableMinimalPerf.default	339	326	1.04:1
TreeMinimalPerf.default	1124	1083	1.04:1
Checkbox.Fluent	605	580	1.04:1
ImageMinimalPerf.default	327	318	1.03:1
ListCommonPerf.default	884	860	1.03:1
ListWith60ListItems.default	1064	1032	1.03:1
Button.Fluent	461	449	1.03:1
ButtonSlotsPerf.default	561	550	1.02:1
ItemLayoutMinimalPerf.default	1488	1452	1.02:1
MenuButtonMinimalPerf.default	1396	1369	1.02:1
PortalMinimalPerf.default	276	271	1.02:1
RadioGroupMinimalPerf.default	524	514	1.02:1
SliderMinimalPerf.default	1298	1268	1.02:1
AccordionMinimalPerf.default	124	123	1.01:1
AvatarMinimalPerf.default	448	445	1.01:1
CardMinimalPerf.default	485	480	1.01:1
CustomToolbarPrototype.default	3414	3375	1.01:1
Icon.Fluent	626	619	1.01:1
ChatDuplicateMessagesPerf.default	373	374	1:1
DialogMinimalPerf.default	1554	1549	1:1
FlexMinimalPerf.default	258	258	1:1
ProviderMinimalPerf.default	619	617	1:1
SegmentMinimalPerf.default	303	302	1:1
SplitButtonMinimalPerf.default	3177	3171	1:1
IconMinimalPerf.default	599	602	1:1
TextMinimalPerf.default	303	304	1:1
TextAreaMinimalPerf.default	394	394	1:1
TooltipMinimalPerf.default	663	663	1:1
Dropdown.Fluent	3038	3023	1:1
AttachmentSlotsPerf.default	1014	1029	0.99:1
ChatMinimalPerf.default	554	562	0.99:1
DropdownManyItemsPerf.default	1207	1220	0.99:1
HierarchicalTreeMinimalPerf.default	875	882	0.99:1
ListMinimalPerf.default	397	399	0.99:1
RefMinimalPerf.default	181	183	0.99:1
ToolbarMinimalPerf.default	771	778	0.99:1
VideoMinimalPerf.default	523	530	0.99:1
CheckboxMinimalPerf.default	2595	2650	0.98:1
DropdownMinimalPerf.default	3019	3086	0.98:1
AnimationMinimalPerf.default	550	565	0.97:1
DividerMinimalPerf.default	302	311	0.97:1
GridMinimalPerf.default	579	599	0.97:1
HeaderSlotsPerf.default	1256	1289	0.97:1
InputMinimalPerf.default	895	934	0.96:1
LayoutMinimalPerf.default	474	492	0.96:1
PopupMinimalPerf.default	225	235	0.96:1
StatusMinimalPerf.default	563	588	0.96:1
TreeWith60ListItems.default	197	205	0.96:1
Dialog.Fluent	1482	1547	0.96:1
EmbedMinimalPerf.default	1840	1927	0.95:1
ListNestedPerf.default	778	819	0.95:1
ProviderMergeThemesPerf.default	1521	1600	0.95:1
Avatar.Fluent	814	855	0.95:1
HeaderMinimalPerf.default	410	437	0.94:1
Text.Fluent	289	306	0.94:1
ButtonMinimalPerf.default	136	147	0.93:1
MenuMinimalPerf.default	577	624	0.92:1

[size-auditor]

Asset size changes

Size Auditor did not detect a change in bundle size for any component!

Baseline commit: 342ef515550dc4067c2b451dd4ae8f2a7bb9d608 (build)