Story: [PAY-846](https://linear.app/n8n/issue/PAY-846) | Related:
https://github.com/n8n-io/n8n/pull/7225
For the S3 backend for external storage of binary data and execution
data, the `getAsStream` method in the binary data manager interface used
by FS and S3 will need to become async. This is a breaking change for
nodes-base.
Depends on: #7092 | Story:
[PAY-768](https://linear.app/n8n/issue/PAY-768)
This PR:
- Generalizes the `IBinaryDataManager` interface.
- Adjusts `Filesystem.ts` to satisfy the interface.
- Sets up an S3 client stub to be filled in in the next PR.
- Turns `BinaryDataManager` into an injectable service.
- Adjusts the config schema and adds new validators.
Note that the PR looks large but all the main changes are in
`packages/core/src/binaryData`.
Out of scope:
- `BinaryDataManager` (now `BinaryDataService`) and `Filesystem.ts` (now
`fs.client.ts`) were slightly refactored for maintainability, but fully
overhauling them is **not** the focus of this PR, which is meant to
clear the way for the S3 implementation. Future improvements for these
two should include setting up a backwards-compatible dir structure that
makes it easier to locate binary data files to delete, removing
duplication, simplifying cloning methods, using integers for binary data
size instead of `prettyBytes()`, writing tests for existing binary data
logic, etc.
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Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>