Stop stripping HTML from issuable titles

The MR and work items views strip HTML from work item titles: if you create a title like Remove <task-button> from task list items, it'll render as:

Remove from task list items

But only on this view! On others it'll show up fine, as expected:

Remove <task-button> from task list items

It appears to be an attempt to partly render Markdown in the title — if you write _hello_ it'll actually get emphasised — but this is out of step with everywhere else in GitLab, and the sanitisation step being applied causes this bug.

Titles should render identically everywhere.