Add cli option to list what plugins are built in hls executable

[jneira]

• Proposed in the matrix haskell channel: https://matrix.to/#/!hskonBonfjiIefqLUV:matrix.org/$r6XqaAxSOTy6_ezML5pr6qwQ0ZbFzJD-vRXi_HfrWyI?via=hpdeifel.de&via=matrix.org&via=rgb.us.eu.org by det0x
• With the motivation of having a explicit way to know what plugins are available in a concrete hls executable (f.e. it would be useful to see what plugins ar included in hls-1.3.0 for ghc-9.0.1)
• We are already listing them when starting the lsp server so it will not be too difficult to add it

[jneira]

Closed by #2139, many thanks @July541