Add alias to GET /conversations/{cnv} endpoint for LH devices

[smatting]

This PR adds an alias for the endpoint

GET     /conversations/{cnv}

at

GET     /legalhold/conversations/{cnv}

and permits legalhold devices access to it.

We use an alias instead of allowing GET /conversations/{cnv} because the nginz acl files are not expressive enough to match only this endpoint (and not e.g. POST /conversations/join)

Checklist:

• Add a new entry in an appropriate subdirectory of changelog.d
• Update nginz config in helm: charts/nginz/values.yaml
• Update nginz config in the demo: deploy/services-demo/conf/nginz/nginx.conf

[jschaul]

If the intention is only to give legalhold access to one thing (read some information), wouldn't it be better to create another (alias) endpoint /legalhold/conversations/{cnv} and whitelist only that? That would restrict what legalhold can do.

[smatting]

If the intention is only to give legalhold access to one thing (read some information), wouldn't it be better to create another (alias) endpoint /legalhold/conversations/{cnv} and whitelist only that? That would restrict what legalhold can do.

Good idea! @dkovacevic, would that work for you?

[jschaul]

If the intention is only to give legalhold access to one thing (read some information), wouldn't it be better to create another (alias) endpoint /legalhold/conversations/{cnv} and whitelist only that? That would restrict what legalhold can do.

Good idea!

Thanks for creating the alias!