b-form-tags input type is always text

### Describe the bug

Looks like input type of `b-form-tags` is hardcoded to `text`. I can't change it via `input-props`.

### Expected behavior

`input-props` should have ability to change `type`.

### Versions

**Libraries:**

- BootstrapVue: 2.2.2
- Bootstrap: 4.4.1
- Vue: 2.6.11

**Environment:**

- Device: Mac
- OS: macOS Mojave
- Browser: Chrome
- Version: 79.0.3945.117