(core) Limit total attachment file size per document

Summary:
- Add a new parameter `Features.baseMaxAttachmentsBytesPerDocument` and set it to 1GB for the free team product.
- Add a method to DocStorage to calculate the total size of existing and used attachments.
- Add a migration to DocStorage adding an index to make the query in the above method fast.
- Check in ActiveDoc if uploading attachment(s) would exceed the product limit on that document.

Test Plan: Added test in `limits.ts` testing enforcement of the attachment limit.

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3374

app/common/Features.ts

@@ -47,6 +47,8 @@ export interface Features {
                                  // Actual max for a document may be higher.
   baseMaxApiUnitsPerDocumentPerDay?: number;  // Similar for api calls.
   baseMaxDataSizePerDocument?: number;  // Similar maximum for number of bytes of 'normal' data in a document
+  baseMaxAttachmentsBytesPerDocument?: number;  // Similar maximum for total number of bytes used
+                                                // for attached files in a document
 
   gracePeriodDays?: number;  // Duration of the grace period in days, before entering delete-only mode
 }

app/common/UserAPI.ts

@@ -394,6 +394,9 @@ export interface DocAPI {
    * @param title Name of the spreadsheet that will be created (should use a Grist document's title)
    */
   sendToDrive(code: string, title: string): Promise<{url: string}>;
+  // Upload a single attachment and return the resulting metadata row ID.
+  // The arguments are passed to FormData.append.
+  uploadAttachment(value: string | Blob, filename?: string): Promise<number>;
 }
 
 // Operations that are supported by a doc worker.
@@ -869,6 +872,20 @@ export class DocAPIImpl extends BaseAPI implements DocAPI {
     return this.requestJson(url.href);
   }
 
+  public async uploadAttachment(value: string | Blob, filename?: string): Promise<number> {
+    const formData = this.newFormData();
+    formData.append('upload', value, filename);
+    const response = await this.requestAxios(`${this._url}/attachments`, {
+      method: 'POST',
+      data: formData,
+      // On browser, it is important not to set Content-Type so that the browser takes care
+      // of setting HTTP headers appropriately.  Outside browser, requestAxios has logic
+      // for setting the HTTP headers.
+      headers: {...this.defaultHeadersWithoutContentType()},
+    });
+    return response.data[0];
+  }
+
   private _getRecords(tableId: string, endpoint: 'data' | 'records', options?: GetRowsParams): Promise<any> {
     const url = new URL(`${this._url}/tables/${tableId}/${endpoint}`);
     if (options?.filters) {