List installed tools when no command is provided to uv tool run

[eth3lbert]

Summary

Part of #4024

Test Plan

Test cases included.

[eth3lbert]

CI failures — seem unrelated to this change.

[T-256]

From Charlie:

I think uv tool run should list the available executables, to start. That seems straightforward.

A tool can have multiple executables installed.

[eth3lbert]

From Charlie:

I think uv tool run should list the available executables, to start. That seems straightforward.

A tool can have multiple executables installed.

Did I misunderstand the issue? I'm not sure I follow your point.

[T-256]

Did I misunderstand the issue? I'm not sure I follow your point.

nvm, my bad. I didn't see the code and from title I thought it's going to list tool names only but not exposed entry points.

[T-256]

Shouldn't it also show a message about what the below list means:
Available tools and executables to run:

[eth3lbert]

Thanks for the suggestion! However, since I'm simply reusing the tool_list, the output will exactly match uv run list. Additionally, if we want to display a message, we would probably expect the output of uv run list to change as well. I can make the change if desired, or perhaps it would be more suitable to make the change in a follow-up PR.