HLSL autocomplete missing common semantics

### What I'm seeing

Common semantics are missing from autocomplete in Rider. A list of missing semantics are:

- `TEXCOORD0` (more generally, `TEXCOORD{n}`)
- `SV_POSITION`
- `POSITION`
- `INTERNALTESSPOS`
- `SV_TESSFACTOR`
- `SV_INSIDETESSFACTOR`

though there may be others. The following screenshot shows the autocomplete suggestions when beginning to type `SV_POSITION`.


If it would be helpful I can provide more screenshots of what appears when I start typing those other semantics.

### Expected behavior

These common semantics would be included as autocomplete suggestions.

### Environmental Setup

- Rider version: `2022.3.1`
- Unity version: `2021.3.16f1` (LTS)
- Jetbrains Rider Editor package: `3.0.18`

The shaders are included in the `.csproj` file in the following way:

```xml

```

Other features are functioning correctly, including code formatting, syntax highlighting, and context-aware features such as recognizing when `#include`'d files are used or not.

Lastly, these shaders are being written in ShaderLab files with a `.shader` extension and are within `HLSLPROGRAM` and `ENDHLSL`.

### Other Notes

Tested on 2 different PCs running Windows 11 and on several different Unity projects.

---

Originally asked here: https://github.com/JetBrains/resharper-unity/issues/216#issuecomment-1384092151

Start by tracing autocomplete handling for ShaderLab .shader files and the HLSLPROGRAM/ENDHLSL region. Compare the semantic suggestions against the listed missing values, including TEXCOORD{n}, and verify that the common semantics appear when typing them in Rider.

Written by the indexing model from the issue text.