TODO: tests

TODO: figure out how to incorporate combobox's search highlighting

TODO: update combobox to dogfood this component

- Write prop docs

- Rename `separator` prop to `ellipsis`

- Tweak ellipsis check to return an empty string / not completely throw and simply error instead

- Resize observer - separate to its own component for performance/readability, + tweak conditional to check for `undefined` rather falling back if `0` (may matter for initial render)

- Rename internal `EuiTextTruncateToWidth` to `EuiTextTruncateWithWidth`

since we're already defaulting to `end`

- clean up storybook props DX some

- clean up useMemo logic for `truncation` and `truncationOffset` props - prefer moving all logic to a single memo that returns multiple values

- majority of testing is in Cypress, since JSdom has no concept of dimensions/width

+ fix resizable story to use inline resize on supported browsers

- at the cost of more repetitive DOM, but I think the tradeoff here is worth it

- that dogfoods `EuiTextTruncate`

+ add support for configuring truncation for all options and individual options

+ remove `title` attr, should alreaedy be handled by EuiTextTruncate

+ opinionated reordering of imports

+ clean up unnecessary `data-test-subj` prop (already inherited from CommonProps)

+ remove `OPTION_CONTENT_CLASSNAME` const by always rendering the `__content` wrapper regardless of render method

- the new utils allowed me to see how to attempt to continue truncating the logic rather than just metaphorically throwing hands in the air!

- `truncationPosition` can't be set back to undefined if it starts as a number

…ethods

+ write more detailed jsdoc comments/descriptions

+ add a Cypress spec to confirm canvas util works correctly

- param should be optional

- apparently has zero fonts in common with my machine, so google fonts it is

+ clean up previous font loading code - we only need 1 weight, and we can use `before()` instead of a mount util

+ harden standalone behavior

+ re-add the font computation method Marco originally had in the canvas class, and require passing in either a font string or a container to compute fonts from

+ example where the perf differences between various recommended mitigations can be tested

- add basic unit test for confirming that the right utils areb eing called

- add missing E2E test for resize observer behavior

- remove truncation error testing from the main component - we're already testing that in the utils unit tests

- reorganize utils E2E tests slightly for readability

- misc wording fixes