Adjusting the 'Add more information' component to only add undefined parameters. The search functionality will be moved to the sidebar in {T263474}. Implement {T261504} and {T263474} before working on this task.
**Requirements**
[x] Rename title to 'Add undocumented parameter' in sidebar and in main component
[x] Add description underneath the title: 'Add an undocumented parameter by typing the name below and clicking to add it to the template'
[x] Change placeholder text in the field: 'Type name of parameter'
[x] Hide dropdown until typing (currently says 'No unused fields')
[x] Add trashcan in sidebar when component is in use, but user has not clicked to add the parameter yet, to remove the dropdown component without having to add a parameter first
[x] After clicking to add a parameter, remove dropdown component and add the parameter to the template, shown in the sidebar as a selected checkbox. Add to the bottom of the list, in the order that they are added.
[x] If an undefined parameter is added, then unchecked, it removes it from the template completely (and outline element disappears). Then it can only be added back by going through the same process
[x] The add parameter component should should always be at the bottom of the content pane, even if other parameters are added while it's visible
[x] When editing an existing template, include any undocumented parameters present in the wikitext, in the sidebar.
Note: validation/notice is added in {T263405}
**Mocks**
{F32363579}{F32363578}{F32363577}