[dtd] add a flag to disable secrets to the `dart tooling-daemon` command

[kenzieschmoll]

When this flag is passed, the file system API should work without checking for project directories, and DTD should operate with the assumption that it does not need to generate a secret or check it anywhere.

This will be used for debugging purposes. When IDEs start DTD, they will still require a secret for setting project directories.

Naming: maybe --disable-secrets or --no-secret.

@CoderDake @bkonyi

This is blocking flutter/devtools#7107

[a-siva]

same question here, why is it an 'area-vm' issue? Sounds like a DTD issue ?

[CoderDake]

@kenzieschmoll How would you feel about this being '--unsecured' instead?

I feel like --no-secret implies that the functions requiring a secret, no longer need one. Which is different from the FileSystem service no longer checking the workspace directories

[kenzieschmoll]

Discussed offline. This is implemented at --unrestricted here: https://dart-review.googlesource.com/c/sdk/+/352921