Implement a blanket implementation for a marker trait.

Basic Example

```rust

[markertrait::markertrait]

pub trait AsyncTask: Send + 'static {}

struct MySendStatic; staticassertions::assertimpl_all!(MySendStatic: Send, AsyncTask); ```

Generated output: ```rust pub trait AsyncTask: Send + 'static {} impl AsyncTask for T {} ````

Sealed example

```rust

[markertrait::markertrait(sealed)]

pub trait AsyncTask: Send + 'static {}

struct MySendStatic; staticassertions::assertimpl_all!(MySendStatic: Send, AsyncTask, SealModuleForAsyncTask::Sealed); ```

Generated output: ```rust pub trait AsyncTask: Send + 'static + SealModuleForAsyncTask::Sealed {} mod SealModuleForAsyncTask { use super::*;

impl<__AsyncTaskImplementor__> Sealed for __AsyncTaskImplementor__
  where __AsyncTaskImplementor__: Send + 'static {}

pub trait Sealed {}

}

[automatically_derived]

impl<__MarkerTrait__: Send + 'static + __SealModuleForAsyncTask__::Sealed> AsyncTask for MarkerTrait {} ````