Add nextest test runner

[mFragaBA]

What should be done?

Use nextest for running both unit and integration test

How should it be done?

You can take a look at what was done for miden base. Essentially,

• Change Makefile.toml to use nextest
• Update github workflows to install nextest
• Add configuration for nextest with sensible timeouts

Also keep in mind we also have integration tests so those should be taken care of as well

When is this task done?

Once we can

• run tests with cargo make that use nextest
• the CI uses nextest as well
• we validate we have reasonable timeout limits

Additional context

We expect that with nextest we'll be able to identify flaky and slow tests more easily.

[mFragaBA]

closing as the issue is already done