[Do not merge] Add section support

[feich-ms]

Add section support in lu file. Fixes microsoft/BotFramework-Composer#733

[vishwacsena]

We have a significant drop in coverage. Need additional tests. We should also review the back-compat issue with always expecting ## to be a sub-section.

[feich-ms]

The test coverage drop mainly comes from newly added CRUD operations in luParser.js. Will add more tests soon.

[vishwacsena]

We can review this once

• Tests are reverting to keep the ## intent so we do not break back-compat
• Remove luParser.js CRUD operations from this PR. Make a separate PR with this + tests.

@feich-ms please update this PR once the changes are in.

[feich-ms]

@vishwacsena

1. I have reverted all the test cases that changed "##" to "#"..

2. The CRUD changes are also removed.

3. The changes in json files of test cases are just related to content order, not content itself

4. if '> !# @enableSections = true' is not added in the header, below content will be identified as two intents(AA and BB, AA is an intent without utterances)
   #AA
   ##BB
   - hello world

   if '> !# @enableSections = true' is added in the header, above content will be identified as section(AA) and sub intent(BB)

5. For the test coverage drop, I have no idea why it drops so much. I looked at the generated report, my newly added functions or contents are covered well by my newly added tests. so maybe @munozemilio can help to take a look? Notice that, all the files under src/parser/lufile/generated folder are auto generated by antlr, so maybe it should not be counted into the report?

[vishwacsena]

@feich-ms We discussed this in BF-CLI review meeting today and decided to take these + other related changes for composer into a composer branch once we are locked down for ignite release (hopefully this week). So marking this as Do not merge. The only changes we want to take to master for now are related to Ignite deliverables.

[feich-ms]

@vishwacsena, Ok, please let me know when the composer branch is ready. Thanks.

[feich-ms]

Close this PR first, since all the composer related changes including section and section CRUD support are in this branch https://github.com/microsoft/botframework-cli/tree/composer now. When it is decided to go into the master, we can create a new PR then.