API improvements to support RushJS integration

[octogonz]

These changes improve logging for microsoft/rushstack#4594.

• To reduce confusion, rename storePath to dotPnpmFolder and avoid referring to it as the "store"
  👉 The PNPM "store" is a different folder from the "virtual store" (.pnpm folder), and PNPM itself is somewhat vague about whether the "virtual store" means the .pnpm folder or actually its subfolder paths

• Fix a bug where postbuildInjectedCopy.sourceFolder and targetFolders were calculated with an extra .. because they were relative to pnpmSyncJsonPath which is a file, not a directory

• pnpm-sync CLI now returns nonzero exit code for errors/warnings

• Add --verbose CLI parameter for testing verbose events

• Provide an importable name for ILogMessageCallbackOptions.details

• Add API docs for IPnpmSyncCopyOptions and IPnpmSyncPrepareOptions

• Rename COPY_PROCESSING to ``COPY_ERROR_NO_SYNC_FILE` to more clearly indicate that it is an error.

• Introduce new log events PREPARE_ERROR_UNSUPPORTED_FORMAT and PREPARE_WRITING_FILE

• Add more details fields to the various log events

• The millisecond timings are now number instead of string to permit the caller to format them

• Remove pnpm-sync: prefix from log messages so the caller can do that

• Improve grammar to avoid a Synced 1 files message

• IPnpmSyncCopyOptions.pnpmSyncJsonPath is no longer optional because API's should not be designed around process.cwd() and also a correct implementation needs to test existence of that file before calling the API

• Remove IPnpmSyncCopyOptions parameter destructuring because this is an implementation detail that clutters the public API docs

@g-chao