"Bind to grammar/schema..." should be a command available from the palette

[fbricon]

Currently, "Bind to grammar/schema..." can only be triggered if xml.codeLens.enabledis set to true.

It makes sense to also expose it as a command available from the command palette

[AlexXuChen]

Lemminx change: eclipse-lemminx/lemminx/pull/1084

[AlexXuChen]

Should be part of 0.18.0