[Mgmt] Add baseUrl customization for track2 SDK

Currently we are using baseUri: options.endpoint || "https://management.azure.com/" in mgmt plane track2 SDK track2 link. which is different from what we did in the track1 SDK link this.baseUri = options.baseUri || this.baseUri || "https://management.azure.com"; I wonder why we remove the support of baseUri customization and use endpoint instead ?

customer suggest us to change it into

baseUri: options.endpoint ?? options.baseUri ?? "https://management.azure.com/"

see original issue here https://github.com/Azure/azure-sdk-for-js/issues/20651

[joheredi]

@bterlson, I think baseUri was inherited from core-http and we didn’t get rid of it 😞 in favor of endpoint. I think the way we can proceed right now is with 3 changes:

1. Fix the generated code so that it honors baseUri, as Brian mentioned, endpoint should win over baseUri if both are present.
2. Add endpoint to the ServiceClientOptions in core-client next to baseUri, also mark baseUri as deprecated to discourage users from using it, so that in the next major bump we take we can remove baseUri
3. Remove endpoint from the generated code as it extends ServiceClientOptions and would get endpoint from there

[qiaozha]

@bterlson I guess this is probably because data plane is using endpoint since track1 and mgmt plane on the other hand is using baseUri. @joheredi feel free to correct me if I am wrong. Thanks