error: ‘std::string_view’ has not been declared

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### My Question

```console
....../Open3D/build/filament/src/ext_filament/include/utils/ostream.h:65:30: error: ‘std::string_view’ has not been declared
65 | ostream& operator<<(std::string_view const& s) noexcept;
| ^~~~~~~~~~~
In file included from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.h:60,
from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.cpp:44:
....../Open3D/build/filament/src/ext_filament/include/filament/Material.h:51:11: error: declaration of ‘using BlendingMode = enum class filament::BlendingMode’ changes meaning of ‘BlendingMode’ [-fpermissive]
51 | using BlendingMode = BlendingMode;
| ^~~~~~~~~~~~
In file included from ....../Open3D/build/filament/src/ext_filament/include/filament/Material.h:22,
from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.h:60,
from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.cpp:44:
....../Open3D/build/filament/src/ext_filament/include/filament/MaterialEnums.h:64:12: note: ‘BlendingMode’ declared here as ‘enum class filament::BlendingMode’
64 | enum class BlendingMode : uint8_t {
| ^~~~~~~~~~~~
In file included from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.h:60,
from ....../Open3D/cpp/open3d/visualization/gui/ImguiFilamentBridge.cpp:44:
....../Open3D/build/filament/src/ext_filament/include/filament/Material.h:52:11: error: declaration of ‘using Shading = enum class filament::Shading’ changes meaning of ‘Shading’ [-fpermissive]
52 | using Shading = Shading;
......
```