tags anchors are generated the same for restapi json

**Operation System**: (`Windows`)

**DocFX Version Used**: 2.52

**Template used**: (`default`)

**Steps to Reproduce**:

1. get attached test.json file
2. generate docfx.json and add `test.json` to the `files`
3. build the doc
4. open http://localhost:8080/restapi/test.html

**Expected Behavior**:
IN THIS ARTICLE right column should have tags generated with unique ids (including tag name I suppose) the same as anchors in the document
AddressApi - http://localhost:8080/restapi/test.html#localhost_64102_testapi_v1_Test_v1_AddressApi
ClientApi - http://localhost:8080/restapi/test.html#localhost_64102_testapi_v1_Test_v1_ClientApi

**Actual Behavior**:
tag name is not included into generated anchor address
AddressApi - http://localhost:8080/restapi/test.html#localhost_64102_testapi_v1_Test_v1
ClientApi - http://localhost:8080/restapi/test.html#localhost_64102_testapi_v1_Test_v1

this causes IN THIS ARTICLE links to point to the same anchor name

[test.json.zip](https://github.com/dotnet/docfx/files/4476390/test.json.zip)