Update Protos

[github-actions]

• Nightly Proto Update

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[graphite-app]

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[macroscopeapp]

Update Protocol Buffer definitions to replace message cursor fields with welcome metadata fields in MLS API welcome messages

• Introduces new WelcomeMetadata message type with message_cursor field in mls.pb.go
• Replaces message_cursor uint64 fields with welcome_metadata byte fields in WelcomeMessage_V1 and WelcomeMessageInput_V1 message types
• Updates OpenAPI/Swagger definitions in mls.swagger.json and payer_api.swagger.json to reflect the field changes from messageCursor uint64 format to welcomeMetadata byte format

📍Where to Start

Start with the new WelcomeMetadata message type definition in mls.pb.go to understand the structural changes to the Protocol Buffer definitions.

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Macroscope summarized e43a223.