[OTA] Add script for generating OTA image (#13547)
[OTA] Add script for generating OTA image (#13547)

Add script for encoding spec-compliant OTA image header
and concatenating a set of payload files.
project-chip/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip