feat: add chunking mode option for BlueBubbles (#1645)

* feat: add chunking mode for outbound messages

- Introduced `chunkMode` option in various account configurations to allow splitting messages by "length" or "newline".
- Updated message processing to handle chunking based on the selected mode.
- Added tests for new chunking functionality, ensuring correct behavior for both modes.

* feat: enhance chunking mode documentation and configuration

- Added `chunkMode` option to the BlueBubbles account configuration, allowing users to choose between "length" and "newline" for message chunking.
- Updated documentation to clarify the behavior of the `chunkMode` setting.
- Adjusted account merging logic to incorporate the new `chunkMode` configuration.

* refactor: simplify chunk mode handling for BlueBubbles

- Removed `chunkMode` configuration from various account schemas and types, centralizing chunk mode logic to BlueBubbles only.
- Updated `processMessage` to default to "newline" for BlueBubbles chunking.
- Adjusted tests to reflect changes in chunk mode handling for BlueBubbles, ensuring proper functionality.

* fix: update default chunk mode to 'length' for BlueBubbles

- Changed the default value of `chunkMode` from 'newline' to 'length' in the BlueBubbles configuration and related processing functions.
- Updated documentation to reflect the new default behavior for chunking messages.
- Adjusted tests to ensure the correct default value is returned for BlueBubbles chunk mode.

src/config/zod-schema.providers-core.ts

@@ -633,6 +633,7 @@ export const BlueBubblesAccountSchemaBase = z
     dmHistoryLimit: z.number().int().min(0).optional(),
     dms: z.record(z.string(), DmConfigSchema.optional()).optional(),
     textChunkLimit: z.number().int().positive().optional(),
+    chunkMode: z.enum(["length", "newline"]).optional(),
     mediaMaxMb: z.number().int().positive().optional(),
     sendReadReceipts: z.boolean().optional(),
     blockStreaming: z.boolean().optional(),