[V4] Updated EventStreams Byte to SByte to be inline with the spec where Byte was intended to be signed.

[boblodgett]

Description

Changed EventStreamHeaderType.Byte to EventStreamHeaderType.SByte to be compliant with the specification that a byte is an Int8 which is a signed 8 bit integer not an unsigned 8 bit integer. Updated unit tests and handling of the SByte.

From the SPEC:

struct {
    select (HeaderValueType) {
        case boolean_true:
        case boolean_false:
            struct {};
        case byte:
            int8 value;
        case short:
            int16 value;
        case integer:
            int32 value;
        case long:
            int64 value;
        case byte_array:
            byte data<1..2^15-1>;
        case string:
            utf8 data<1..2^15-1>;
        case timestamp:
            int64 millis_since_epoch;
        case uuid:
            byte value[16];
    } value;
} HeaderValue;

The fixed unit test should have been testing a -47 which it couldn't have done as an unsigned byte.

Motivation and Context

https://sim.amazon.com/issues/DOTNET-7943

Testing

• Fixed Unit Tests.
• DryRun: DRY_RUN-a606d350-0953-430b-834d-8565a689965f

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license