Expand `vector generate` pipeline syntax to accept arguments

Something that came up recently, specifically for our guides, is the ability to start Vector without passing a vector.toml file. This would be useful for very simple pipelines and examples. We already have a short-style syntax for vector generate:

vector generate 'stdin | aws_s3`

The config generated from this command requires manual modification because required arguments are not set, like the S3 bucket. What if the generate syntax could accept arguments? Then this would work:

vector $(vector generate 'stdin | aws_s3 --region="us-west-1" --bucket="my_bucket" --request.batch_size=10000000')

And if that works, we might as well support inline configs as an argument:

vector 'stdin | aws_s3 --region="us-west-1" --bucket="my_bucket"' --request.batch_size=10000000

I'm curious what people think about the possible syntaxes:

1. Bash style / command line syntax (my favorite)
2. A URL syntax like Apache Camel uses.
3. Any others?

To be clear, this is for simple linear pipelines and should not support complex cases. The vector.toml syntax is designed for more complex pipelines.

Start with the existing vector generate short-style pipeline syntax and the CLI entry points that parse it. Compare the proposed Bash-style arguments, URL syntax, and inline configuration, then define the supported scope for simple linear pipelines and verify the examples in the issue.