Improve error message when packages can't be downloaded

[banool]

Repro

# Disallow writes to the `.move` directory.
$ rm -rf ~/.move/
$ mkdir ~/.move
$ chmod 555 ~/.move

# Try to publish
$ ~/a/core/target/debug/aptos move compile --named-addresses token_objects=0x1
Compiling, may take a little while to download git dependencies...
FETCHING GIT DEPENDENCY https://github.com/aptos-labs/aptos-core.git
{
  "Error": "Move compilation failed: Unable to resolve packages for package 'TokenObjects': While resolving dependency 'AptosFramework' in package 'TokenObjects': While processing dependency 'AptosFramework': Unable to find package manifest for 'AptosFramework' at \"/Users/dport/.move/https___github_com_aptos-labs_aptos-core_git_mainnet/aptos-move/framework/aptos-framework\""
}

This error doesn't really explain the root cause, it'd be better to do an explicit check if writes are possible first and raise an error based on that.

[banool]

Rolled into #8707.