Fix sizing of elements.

[Jl5her]

Description

Tables that exceed the main container of the website stretch and users cannot see all the content.

• we need to implement flexbox in abacus
• make a .scss file in frontend/src/pages/admin/submissions and import it into submissions

Steps to reproduce

On a smaller screen or window go to a page that has a contentful table.

Expected result

Table or margins should scale to fit the content.

Actual result

Content overflows and becomes not visible, and inaccessible.

Evidence