lsp-xml: add supports for native binary language server

[kiennq]

The xml language server that's created by Redhat doesn't require Java.
We can add that as a compliment to the current jar version.

Looking at the vscode, it does the switch between jar version and native version based on java is available or not, I used the same approach here instead of creating a new xml language server declaration.

[kiennq]

@jcs090218, @yyoncho, the test for 26.x is not running due to it has been dropped from support.
Can you remove those rules for merge as well?

[jcs090218]

I don't have the permission. @yyoncho and @ericdallo have it.

[ericdallo]

@jcs090218 I gave you owner permission too, since you are quite active in lsp-mode for some time :)

[jcs090218]

@jcs090218 I gave you owner permission too, since you are quite active in lsp-mode for some time :)

That's very kind! Thank you! :D

[jcs090218]

Can you remove those rules for merge as well?

@kiennq It's gone now. :)

[jcs090218]

There are compile errors:

In toplevel form:
lsp-xml.el:355:1:Warning: defcustom for ‘lsp-xml-server-command’ fails to
    specify type
lsp-xml.el:355:1:Warning: defcustom for ‘lsp-xml-server-command’ fails to
    specify type