Add Text viewer

[networkfusion]

Description

Adds a basic text viewer. It does not (yet) support full file content. superseeds #21

Motivation and Context

There were too many changes to merge from the original PR.

How Has This Been Tested?

On an SC64 via devcontainer.

Screenshots

Types of changes

• [x] Improvement (non-breaking change that adds a new feature)
• [ ] Bug fix (fixes an issue)
• [ ] Breaking change (breaking change)
• [ ] Config and build (change in the configuration and build system, has no impact on code or features)

Checklist:

• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

Signed-off-by: GITHUB_USER