Set the OTA data block size in the VS Code extension

[georgevbsantiago]

Currently, we can only set the OTA data block size in the device firmware using the ota.set_block_size() method. However, it would be more flexible if the VS Code extension set this size from pre-registered values ​​(for selection in a combobox: 256, 512, 1024, 2048...), since this option would not depend on a specific user implementation in the device firmware.

And this functionality is important, because some devices cannot perform the OTA process with the default configuration of the Arduino-Thinger library due to low WiFi signal power or due to too much electromagnetic interference (EMI).

In these cases, the user could change the data block size directly in the VS Code extension to succeed in the OTA process.

Problems in the OTA update process were reported in this issue:
thinger-io/Arduino-Library#51