Replace +{SHA} with .{SHA} in lerna publish --canary

Description

Instead of using plus (+) sign in package name provided by --canary flag, use dot.

Motivation and Context

It's not possible to publish --canary version into jfrog artifactory, as jfrog is cutting part of filename, due to + (plus) character. So, instead of using +, I would suggest to use dot.

#2060

How Has This Been Tested?

Unit tests
Integration tests
Run publish command

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (change that has absolutely no effect on users)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.