* [core] Normalizing vendor extension naming
According to [OAS 2.0][1] and [OAS 3.0][2] Specifications:
> Allows extensions to the OpenAPI Schema. The field name MUST begin with x-,
> for example, x-internal-id. The value can be null, a primitive, an array or an object.
> Can have any valid JSON format value.
This commit attempts to define a [clear identifier design format][3] of
maintaining lower-kebab casing and following the x- prefix defined by
OAI Specification.
Following a convention that matches that used by others (see [autorest][4]), we will remove
any confusion about naming strategies for template authors and
customizers. Following the lower-kebab convention will allow us to
convert from camelCase and missing prefixes to the desired format. For
example, these conversions are simple to make for template consistency:
* customValue => x-custom-value
* x-customValue => x-custom-value
* x-custom-value => x-custom-value
This convention also allows us to define a single standard for use
across all generators. This means no occurrence of x-operationId in one
generator and x-operation-id in another.
[1]: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#patterned-objects
[2]: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#specificationExtensions
[3]: https://tools.ietf.org/html/draft-wilde-registries-01#section-3.4
[4]: https://github.com/Azure/autorest/tree/master/docs/extensions
* Incorporate feedback to avoid race/blocking in OnceLogger
* Remove unnecessary additional log config
* Add tests,comments for OnceLogger
* Test caffeine cache with FakeTicker
* [cli] Write to stdout/stderr, allow redirection
Previously, slf4j-simple from generator core was being used. This writes
to only a single stream (STDERR) and is confusing from a CLI tooling
perspective.
This consumes logback in CLI, and excludes core's slf4j-simple
dependency. This allows us to define multiple appenders, one for STDOUT
and one for STDERR.
WARN messages and lower are written to STDOUT. ERROR is written to
STDERR.
* [cli] Limit logs to match prev implementation
* Remove slf4j-simple from core project, to avoid conflicts with consumer logger implementations
