[Bug] az pipelines [create|list] --folder-path is inconsistent in how it handles forward slashes

When creating a pipeline the --folder-path parameter will sanitise `/` into `\` and create the pipeline at the expected path.

When listing pipelines the --folder-path does not sanitise the path separators and returns no results if you use `/`.

I think this is confusing.

**To Reproduce**
azure-cli 2.7.0
azure-devops 0.18.0

PS > `az pipelines create --folder-path "pipeline/folder" --name "test"`
PS > `Successfully created a pipeline with Name: test, Id: 420.`

PS > `az pipelines list --folder-path "pipeline/folder" -o tsv`
[No Output]
PS > `az pipelines list --folder-path "pipeline\folder" -o tsv`
`test`

**Expected behavior**

PS > `az pipelines create --folder-path "pipeline/folder" --name "test"`
`Successfully created a pipeline with Name: test, Id: 420.`

PS > `az pipelines list --folder-path "pipeline/folder" -o tsv`
`test`
PS > `az pipelines list --folder-path "pipeline\folder" -o tsv`
`test`