feature: Update agenda component to the fluent UI spec (#1867)

* fix: Filter people to avoid id property failing on null values

* update: Use fluent-card and styling for fluent UI update

* update: Style the header when group-by-day is used

* update: Use fluent-card for the loading cards

* update: Make the mobile version responsive

* update: Add a tooltip for the headings

* update: Change the CSS for agenda to reduce unused classes

* update: RTL CSS to a modular CSS layout and fix initial RTL issues

* update: CSS for high contrast modes and fix location icon colors

* update: usage of the narrow class to make it easier to style nested elements in small viewports

* update: to use classMap for multiple conditional classes

* update: use a divider to make the highlight around a card not to overflow at the bottom

* update: style loading elements card

* Update packages/mgt-components/src/graph/graph.presence.ts

Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>

* update: add a new CSS prop --event-row-gap and remove the row divider

* update: use gap and flex to space the events and fix spacing in grouped events

* update: show contact card over event card on hover/focus of person

Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>

* update: set the card width to <100% to remove the horizontal scroll in storybook

* update: generated react source

* update: Make the tooltip hover over the content

* update: set tooltip is description is available

* chore: fix export name for lit decorators

* fix: set the max people shown to 5

* fix: remove checking for nulls in people returned

* fix: get from cache after first request and skip unnecessary graph calls

* fix: change location icon to 24px svg and set WxH to 12px

* feat: add new custom style for agenda

* feat: create a new css prop for agenda attendees

* fix: use padding-left to move template from overlapping text

* fix: set padding-left=0px in narrow CSS mode

* fix: make the bg color transparent.

Only set the background color to what the developer sets in the CSS

* fix: change to padding-inline-start property and remove margins

* refactor: set the fallback details after failing to get a graph res

* refactor: use optional chaining in condition

Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>

* refactor: use already declared bool value

* refactor: use optional chaining in condition

Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>

* refactor: import from a file and sort imports

* fix: set auto width on the tooltip

* fix: smaller layouts width

Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>

* refactor: to have only 2 blocks when checking values from cache

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Co-authored-by: Gavin Barron <gavinbarron@microsoft.com>