Skip extensions with multiple versions

[Ebsan]

Until we find a better way to handle multi-versioned extensions this will skip them entirely. I've also added another exception handler to the retry logic. Discussed in #19

Currently this logic skips about 16 extensions. So we might want to put a message somewhere about this?

Skipped extensions (as of 10/26/2021):

• actboy168.lua-debug
• redhat.vscode-openshift-connector
• BlockceptionLtd.blockceptionvscodeminecraftbedrockdevelopmentextension
• AlbinBD.run
• xsro.vscode-dosbox
• joaomoreno.vscode-platform-specific-sample
• axetroy.vscode-whatchanged
• sandy081.998-test-code
• yanzh.sample
• chrmarti.test-platform-specific-extensions
• AndresMorelos.compliance-debug-syntax
• sandy081.998-test-web-only
• RemiOlivier.pkcs11-explorer
• JoonaYoon.LFS
• sandy081.999-pse-win
• PrashantCholachagudda.eardemo

[Ebsan]

This pull request was closed because #21 correctly handles multiple versions and we don't need to skip them anymore.