Support a configurable version of redoc.standalone.js for preview-docs

Is your feature request related to a problem? Please describe.
At times, the latest version of the redoc.standalone.js bundle can contain bugs. This is the situation right now, with 2.0.0-rc.72, which has several bugs. Preview-docs references https://cdn.jsdelivr.net/npm/redoc@latest/bundles/redoc.standalone.js, with no option to override it.

Describe the solution you'd like
An additional optional parameter to specify the standalone.js version.
For example redocly preview-docs ./petstore.yaml --standalone-version=2.0.0-rc.58

This would result in https://cdn.jsdelivr.net/npm/redoc@2.0.0-rc.58/bundles/redoc.standalone.js being used instead of https://cdn.jsdelivr.net/npm/redoc@latest/bundles/redoc.standalone.js.

Describe alternatives you've considered
I have not found other good alternatives. When publishing the documentation, we can always point to the desired version, but we would like to have the same experience when designing and testing the documentation using preview-docs.

Additional context
The affected code is to be found here:
https://github.com/Redocly/redocly-cli/blob/67c53ee8e75a6ca002d6aaaa889adcca0507d8bd/packages/cli/src/commands/preview-docs/preview-server/preview-server.ts#L37

Start with packages/cli/src/commands/preview-docs/preview-server/preview-server.ts at the referenced line, then trace how preview-docs options are defined and passed into the preview server. Add the optional standalone version path described in the issue, and verify that the generated URL uses it instead of the latest bundle when provided while preserving the current default.