Move soft dependency on `MultiAssayExperiment` into `teal.data`

[pawelru]

After https://github.com/insightsengineering/teal/pull/1051 on pre-release branch we are using MultiAssayExperiment only in:

• tests of deprecated functionality (tdata())
• vignette "Including Data in teal Applications"

(please note that it's not used in any of the functionality)

Can we remove it out of teal? The latter is important but I feel is more appropriate for ~teal.data~ teal.slice.

[chlebowa]

I think you mean teal.slice, teal.data has nothing to do with the class of objects put into the container.

[pawelru]

Yes - you're right - it's teal.slice

[chlebowa]

MAEs are still used in example apps in teal, albeit the chunk is set to eval=FALSE.

https://insightsengineering.github.io/teal/main/articles/including-data-in-teal-applications.html