Do not allow publishing extensions with invalid semver versions

[sandy081]

Recently we found out that Marketplace is allowing extensions with versions which are not SemVer compatible. Example - https://marketplace.visualstudio.com/items?itemName=perfsee.perfsee-vscode
This extension has version 2022.09.290700 which is invalid. According to SemVer any part of the version should not start with 0. vsce is validating the version before publishing, so I believe one should have uploaded this VSIX to marketplace instead of going via vsce. So, I suggest following changes

1. Do not allow publishing extensions with invalid versions
2. Come up with a strategy to fix existing extensions with invalid versions.