Enhancement: Custom browser tab ID replaces product_name

[TonyGravagno]

Ref #4972 (comment) and the follow-ups about using Containers in Firefox to open tabs to multiple accounts with Roundcube.

When doing this, with $config['product_name] set, the window/tab title is the same for all instances. I think it would be helpful to see an account-specific title so that we can distinguish which tab is open to a specific mail account.

In Roundcube the browser title is already changed on a per-page basis, and to show the current count of items in a folder.

With this request I'm suggesting an enhancement for an option that uses account-specific text in the header, rather than the product_name. The initial implementation would offer a new account-specific configuration option with nothing but a text field to replace the product_name. For example: "Browser Title: [FooAdmin]". The text FooAdmin, provided by the user, will then be used rather than the product_name whenever the title is changed. That would result in "(39) FooAdmin :: Inbox". Of course this only applies to logged-in accounts. The login page (others?) would still render the default product name.

Perhaps in a second round, this can be enhanced to support dynamic data, like %d for domain, %a for account, %n for account name, etc. But I believe the first version should only allow static text. There is a very limited amount of space for the title in a tab marker. A long user name or domain name would be as unhelpful as the product name. I think dynamic title text should be a follow-up enhancement after the static base is implemented. People might think of other dynamic text to include later. Also, if two tabs are open, with users admin@foo.tld and admin@bar.tld for example, then %a would be "admin" in two tabs which would not be helpful. The text needs to be substring-replaceable, like "%a foo" and "%a bar" so that the user can adjust what's rendered for their own purposes. This complication doesn't need to be in a first version.

If there is some agreement about the value of this, I'll take a shot at publishing a PR.

[alecpl]

I guess a config option product_title that defaults to product_name with mentioned replacement variables support would make sense. And it would make sense that users can change the config via Preferences > User Interface > Browser options.