Provide a silent_installs boolean config key for installing the list of servers in ensure_installed table

[krishnakumarg1984]

Is your feature request related to a problem? Please describe.

Currently, ensure installed echoes a message for each server to be installed in the ensure_installed list. This is a bit annoying (even if it is a one-off), especially when we have lots of servers to be installed on a slow network connection. This is even more annoying when using the nvim-notify plugin since multiple message boxes are opened all over the place mimicking the user experience of a hijacked Internet Explorer experience with pop-ups all over the place.

Describe the solution you'd like

Provide a config key to nvim-lsp-installer, e.g. silent_installs = false | true. The default value of the key may be set appropriately to retain the current behaviour, while providing users with the ability to tweak the installation to their tastes.

Describe potential alternatives you've considered

No response

Additional context

No response