feat: add an identifier for pnpmSyncPrepare

[g-chao]

Summary

Support an optional parameter lockfileId when calling the pnpmSyncPrepareAsync API.
The purpose of this parameter is let pnpm-sync to recognize the entries in the .pnpm-config.json file, so that the pnpm-sync can update these entries correctly, also be able to remove invalid entires

Details

When calling the pnpmSyncPrepareAsync API, how does pnpm-sync know which entries need to be update in the .pnpm-config.json? Especially in a large Monorepo with Rush subspace feature enabled where there could have tens of pnpm-lock.yaml files.

Previously, when generating the .pnpm-config.json, pnpm-sync read the existing entries, only append new unique entires there. This is to ensure the tool doesn't delete entries where could belong to other pnpm-lock.yaml. But, it has a drawback where, since it does not delete any entries, it is possible, in your local development, there could be some invalid entries in the .pnpm-config.json due to frequently pnpm-lock.yaml changes. It might cause issue as time goes by, and when it happens, you will need to manually delete .pnpm-config.json file or node_modules to regenerate them. It brings inconvenience.

In this PR, we add a optional parameter identifier when calling the pnpmSyncPrepareAsync API. So that, the pnpm-sync could recognize the pnpm-lock.yaml file it processed, then it able to delete the invalid entries in the .pnpm-config.json to avoid unnecessary or invalid sync actions in the later steps.

[octogonz]

@g-chao I think it would also be useful to provide a way to delete unknown identifiers, for example if a Rush subspace was deleted.

The setting could be like:

/** 
  * The identifier to be prepared by this operation.  If it an entry already exists with this name,
  * then it will be replaced.
  */
"identifier": "subspace2",

/** 
 * Instruct the API to delete any identifiers that don't appear in this list.
 */
"pruneIdentifiersExcept": [ "subspace1", "subspace2", "subspace3" ]

Since my idea here is basically a separate feature, maybe it could be introduced later as a separate PR. Along with a corresponding CLI like:

pnpm-sync prepare --prune-identifiers-except subspace1,subspace2,subspace3

or

pnpm-sync prune --except subspace1,subspace2,subspace3

[g-chao]

We need to pass pnpm-lock.yaml to pnpm-sync prepare. So in the below example won't work, unless we pass ALL pnpm-lock.yaml files to the command, which is not intended.

pnpm-sync prepare --prune-identifiers-except subspace1,subspace2,subspace3

In the situation that Rush subspace was deleted, the identifiers related to this subspace will be deleted as well along the regular rush install/update events