Support adding any custom attribute to mj-components such as amf:repeater

[toddpadwick]

Is your feature request related to a problem? Please describe.
Adestra allows custom attributes like amf:repeater or amf:editable to components. so I have tried to do this like so:

<mj-section amf:repeater="Articles">
</mj-section>

or

mj-image amf:editable/>

but these attributes get stripped by MJML.

Describe the solution you'd like
allow all attributes added to mj components to be passed down to the rendered child html node.

Describe alternatives you've considered
I am aware you can wrap raw code like so:

<mj-raw><table amf:repeater="articles"></mj-raw>

<mj-raw>
<img amf:editable/>
</mj-raw>

but this means we can't make use of mjml's components to means theres little benefit of using MJML.

Additional context
View adestra template documentation here.