Respect ignorePatterns in getPackageInfos

[ecraig12345]

#761 added error checking for duplicate package names, which accidentally caused issues in workspace-tools when trying to update beachball (see microsoft/workspace-tools#172 (comment)).

workspace-tools is a single package, but it has some other test fixture monorepos inside it. Because getScopedPackages has to scan for non-workspace monorepos before assuming a single package setup, workspace-tools is getting detected that way and there's an error because several fixture packages share a name.

One way to fix this is to respect the ignorePatterns option when scanning for packages. This adds a bit of cost but is probably the right thing to do, and will likely help avoid other subtle issues in the future with similar fixture setups.

NOTE: The actual fix is simple (in src/monorepo/getPackageInfos.ts) but a LOT of references needed to be updated due to the signature change.