* [VS Code] Update json schemas for apiProperties.json and apiDefinition.swagger.json
* - Added more swagger schema changes that are available, but not used in OSS repo yet.
* - Remove `patternProperties/^x-ms-` so errors in Problems window shows "Property x-ms-... is not allowed", instead of "Matches a schema that is not allowed.", which is more ambiguous and may be other problem.
- Set our custom schemas so their ids point to the raw schema file.
The initial ids were to an html page. The new ids point to the raw file download.
- added support for the optional "$schema" property so loose files can still get intellisense.
Swagger schema updates:
- Added snippets for swagger $ref properties.
- Added support for `x-ms-pageable`
- Added support for `x-ms-enum-values`
- Added enum for `format`
apiProperties schema
- Added policy template `updatenextlink`
- Added some snippets for policy templates
- Remove erroneous definitions of `x-ms-apimTemplate-policySection`
* [VS Code] Add schemas for common files
- settings.json (paconn settings file)
- apiProperties.json
- apiDefinition.swagger.json
The schema for apiDefinition.swagger.json files is modified from the one found at http://schemastore.org/json/.
It includes many 'x-ms-' vendor extensions.
* [apiDefinition.swagger.schema.json] Copy from http://schemastore.org/json/