Background
Currently, the dialog header titles and button text are reactive to content. We want to keep this same behavior, but adjust the text that is shown.
States
| Action | Current Title | New Title | Mock | Current Button Text | New Button Text |
| When inserting a new template. Shown after clicking Insert > Template, while on the search screen. | Add a template | Insert a template |  | Insert (disabled) | no change |
| After choosing a new template to insert, while filling out template. | {Template name} | Insert: {Template name} |  | Insert | no change |
| When editing an existing transclusion already present on a page | {Template name} | Edit: {Template name} |  | Apply changes | Save |
| When editing an existing transclusion with multiple parts (template+wikitext or more than one template) | Transclusion | Template content |  | Apply changes | Save |
| When editing on mobile | - | The header titles should match the updates above. If the title is too long on mobile screens, it should be truncated. |  | Checkmark | no change |
Relevant prototype commits:
