Fine tune all search blocks

[carolinan]

Description
Currently the patterns that use search forms are using 3 different styles:

<!-- wp:search {"label":"Search","showLabel":false,"widthUnit":"%","buttonText":"Search","style":{"border":{"radius":"100px"}},"fontSize":"small","borderColor":"opacity-20"} /-->

<!-- wp:search {"label":"Search","showLabel":false,"buttonText":"Search","style":{"border":{"radius":"50px"}},"fontSize":"medium","borderColor":"opacity-20"} /-->

<!-- wp:search {"label":"Search","showLabel":false,"buttonText":"Search","style":{"border":{"radius":"50px"}},"fontSize":"medium"} /-->

Lets try to find a way to remove the border radius from the block markup, and make sure that the border radius and border color matches. This is needed because when we start adding the style variations, they need to be able to override the styles of the inputs. See for example: https://www.figma.com/design/dzGCSntVch4EQdVERTqyVK/Twenty-Twenty-Five?node-id=77-650&m=dev

Search form blocks that do not have a visible label, still needs the "label" attribute to contain the word "Search" and this should also be translation ready.

Two of the blocks uses font size medium and two uses font size small. The default font size in theme.json is medium,
so these blocks do not need the font size to be added in the pattern.

[carolinan]

I found the following issue and pull request in the Twenty Twenty-Four repository:
WordPress/twentytwentyfour#389
https://github.com/WordPress/twentytwentyfour/pull/398/files

It shows a bug with the styling of the forms, that is still not solved.