This PR prepares Matomo for better reports on used clients. Currently Matomo shows all clients that are not detected as a browser as
Unknown. With this changes the column that currently stores the browser short code will be increased in size, to be able to store full client names. Additionally there will be a new column to store the client type (represented with an int id).
Besides changing the database I've also decided to already store the full name for clients (other than browsers). That way those other clients will already appear in the "Browsers" reports. That might not be fully correct, but imho better than report them as unknown. The client type will also be set already, but should be invisible everywhere (except from custom reports maybe)
Note: It's currently not possible to segment for those other clients, as the browser segment still only accepts the short codes. That's something we can add later, when we possibly also add new reports for each client type or so.