[Autocomplete] Only activate clear button plugin when there is a placeholder option

[Qronicle]

Q	A
Bug fix?	yes
New feature?	maybe?
Issues	Fix #402
License	MIT

Only add the clear_button plugin to TomSelect if the form element has no placeholder option.

Notes:

• I defined 'having a placeholder' as the select having an option with an empty value, as that is what TomSelect also seems to do
• I'm not 100% sure about whether this needs a test or how to even run tests locally

[smnandre]

Form the monorepository root

Install dependencies

yarn install 

Code style

yarn run lint
yarn run format

Run Tests

yarn run test

Build dist packages

yarn run test

(you need to commit both src/Autocomplete/assets/src/** and src/Autocomplete/assets/dist/** files in this PR)

Please ask if you want/need anymore information :)

[Kocal]

Status: Needs work

[Qronicle]

Sorry guys, I somehow missed the review notifications. Will try and clear some time to dive back into this.

[smnandre]

No worry, we cannot criticize anyone on time things .... 😅

(well, we cannot criticize anyone on anything just to be clear 😄 )

[LucileDT]

@Qronicle do you have a bit of time to fix your PR? :eyes:

[Kocal]

I am closing due to inactivity, feel free to re-open the PR if necessary. Thanks for the contribution!