gRPC Request: Headers ending with -bin does not convert value to Buffer object.

### Expected Behavior

Adding a new header ending with '-bin' should convert the 'Value' column value into Buffer object.

### Actual Behavior

When sending a request, the following error is shown:


### Reproduction Steps

1. Create 'New Request'
2. Select 'gRPC'
3. Select folder/file containing protos
4. Enter valid url pointing to grpc service
5. Select method to execute
6. Selected 'Headers' tab
7. Add new header, make sure it ends with '-bin'. Example: 'x-custom-bin'
8. Supply base64 value
9. Click 'Send'

### Is there an existing issue for this?

- [X] I have searched the [issue tracker](https://www.github.com/Kong/insomnia/issues) for this problem.

### Additional Information

Reproduced on macOS as well.

I did some digging and this is required by grpc-js package. Even though it isn't the 'right' fix, it did seem fairly easy to detect that header ends with '-bin' and converting the base64 value into a Buffer object. Then everything works great (in my own tests)

### Insomnia Version

2022.2.1

### What operating system are you using?

Windows

### Operating System Version

Windows 10

### Installation method

Download from insomnia.net

### Last Known Working Insomnia version

_No response_

Start at the gRPC request path that assembles outgoing headers and inspect how grpc-js receives header values. Reproduce the request with a base64 value in a header ending in '-bin', then add coverage for the expected binary value and verify the request succeeds.

Written by the indexing model from the issue text.