add go.mod and separate services into independent modules

[joshgav]

Feature Request

Investigate and adopt modules for this and the go-autorest repo.

Strongly consider splitting every service in ./services into separate modules/packages so they can be versioned independently.

[joshgav]

cc @tombuildsstuff @feiskyer

[jhendrixMSFT]

Since each API version within a given RP can independently version we will have to release each RP/API version as a separate module.

[tombuildsstuff]

@joshgav sorry for the delayed reply here - is the intention/thought here that we'd be able to have SemVer within a version of an RP within the services folder, or to split these packages out altogether?

[jhendrixMSFT]

@tombuildsstuff Each API version within an RP will be its own module since they independently rev.

[jhendrixMSFT]

Related: #2564

[LorbusChris]

There has been no movement in https://github.com/Azure/azure-sdk-for-go/projects/2 for 3 months. Is there anything that can be done to speed things up?

[RickWinter]

Completed in track2 will NOT be backported to track1.