Completely distinguish "global site id / global site key", "site database name", "site domain", "site language code", "site subdomain"
We should completely not using string processing for
* "global site id / global site key"
* "site database name"
* "site domain"
* Wikibase Repository sitelink "site-group-language(s)"
and
* "site group"
* "site DB suffix"
and
* "site language code"
* "site subdomain"
For example:
* "global site id / global site key" => `be_taraskwiki`
* "site database name" => `be_x_oldwiki`
* "site domain" => `be-tarask.wikipedia.org`
* Wikibase Repository sitelink 'site-group-language(s)" => `wikipedia => be-tarask`
** Another example => `wikipedia => hak + hak-hant + hak-latn`
and
* "site group" => `wikipedia or special`
* "site DB suffix" => `wiki`
and
* "site language code" => `lzh`
* "site interlanguage prefix" => `lzh` (expected) / `zh-classical` (as for now)
* "site subdomain" => `zh-classical` (as for now)