Locale Fixes

[mdrichardson]

Fixes #2093
Fixes #2032 (most of this was done in this PR, except for one tiny change to SkillHandler.

Description

• Adds locale for EndOfConversation events and activities
• Adds locale to ConversationReference

Testing

Added checks for locale in existing tests.

[mdrichardson]

I had to make a change to this test because instead of an activity with no locale coming back as:

{
  ...
  text: 'blah'
  ...
}

...it would come back as:

{
  ...
  text: 'blah',
  locale: undefined
  ...
}

I'm a little worried that activity.locale = reference.locale (in the above changes) could be a rare breaking change (should really only happen with something like assert.deepEqual() or if (activity.locale !== undefined)(?). This could be fixed by using something more like:

if (!reference.locale) { activity.locale = reference.locale; }

...but I figured the very low risk made the readability okay. Let me know if you feel otherwise.

[coveralls]

Pull Request Test Coverage Report for Build 125203

• 5 of 5 (100.0%) changed or added relevant lines in 3 files are covered.
• 9 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.07%) to 79.707%

---

Files with Coverage Reduction	New Missed Lines	%
libraries/botframework-streaming/src/webSocket/webSocketTransport.ts	2	80.65%
libraries/botframework-streaming/src/webSocket/webSocketServer.ts	7	66.67%

Totals
Change from base Build 125201:	-0.07%
Covered Lines:	12303
Relevant Lines:	14728

---

💛 - Coveralls

[Stevenic]