Remove the special treatment of span.title in Installation Assistant
Originally, the reasons for it was to make it possible to use bold and underline on some words in the titles. But: - Expert UX review told us that underline text was very often confused with links, while these titles are not clickable. - Bold is meant to easy scanning in text but headings should be themselves short enough not to need additional scanning. - They were style and aligned differently that everywhere else on our website and this inconsistency was no backed up with any good argument. - Their content was 100% duplicate from [[!meta title and already caused painful maintenance work. So let's get rid of them, simplify our code, reduce content duplication, and increase style consistency.