Add storage management commands for RevisionE panels

[emaspa]

Fixes #15

[emaspa]

Update: ReadStringResponse improvements

Following up on the ReadTo() timeout discussion, I've reworked ReadStringResponse to fix the storage management performance issues:

Problem: The original ReadResponse loop with a 5-second timeout blocked for the full duration waiting for bytes that never come, making storage operations very slow.

Solution: Rewrote ReadStringResponse with a looping read using short inter-read timeouts:

• First read waits up to readTimeout (configurable per-call) for data to arrive
• After first data arrives, switches to 50ms timeout for subsequent chunks
• Stops when no more data within 50ms, avoids the long blocking wait

This matches the approach used by the ShinySnake/TURZX apps (RJCP.SerialPortStream with ReadTimeout=100ms and a single Read() call). The key insight is that the device sends responses quickly and completely, a short timeout is sufficient.

Additional changes in this update:

• ReadTo() byte-by-byte reads cause timeouts on CDC ACM serial ports (CT13INCH) — kept as unused method for now, ReadStringResponse handles all storage responses
• Added CancellationToken support to UploadFile with chunked writes (4KB) for cancellability
• DiscardInBuffer() after upload/delete to prevent leftover data from corrupting subsequent responses
• Increased timeouts for flash-dependent commands: CreateFile (5s), DeleteFile (5s), QueryStorageInfo (2s), ListDirectory (2s), upload completion (10s)