No autocompletion and hover information in `gql` documents in Vue SFC

**Intended outcome:**

Autocompletion and information on hover in document preceded with a `gql` tag in `.vue` files.

**Actual outcome:**

No autocomplete suggestion nor tooltips.

**How to reproduce the issue:**

Create a `.vue` file (like `MyComp.vue`) in the project, then write

```vue

import gql from 'graphql-tag'

const QUERY = gql`

`

```

**Versions**

vscode-apollo 1.5.2

Use the supplied MyComp.vue example with vscode-apollo 1.5.2 and verify the missing completion and hover behavior. Then trace the extension's handling of gql-tagged documents inside Vue SFCs; done means autocomplete suggestions and hover tooltips work in that example.

Written by the indexing model from the issue text.