Add version flag to update-pjs scripts

[TarikGul]

When calling substrate-update-pjs-deps there is no way to currently specify a version you would like to set the packages and resolutions too. It would be nice to be able to pass in a flag, and it will update all the version to the set value. To implement this would be pretty straight forward, as no fetching is required. In main() we would just have a quick check that says something like argv.version || fetchRelease()['tag_name']

[mlshv]

Hello there! I'd like to contribute on this issue. But I don't get how it is supposed to work. As I can see, not all the @polkadot packages have the same version number.

For example, how do I set version of @polkadot/apps-config?

@TarikGul

[TarikGul]

Great point, that is totally correct and a good catch. We'll have to specify a package group as well. Maybe we set the flag for the package too --packageVersion -> which the value passed in could be expected to be like: apps-config@3.1.1, that way we know the package, and the corresponding version.

[TarikGul]

Would take some simple parsing/splitting but that's the first thing that came to mind