[Bridges SDK] Permissionless dedicated bridge lanes

[acatangiu]

Description

Introduce a new "permissionless lanes" feature, which allows for the dynamic management of opening and closing lanes instead of the current method of hard-coding them in the source code.

Allows parachain teams to have dedicated point-to-point XCM channel between two sides of the bridge (option 2 in DotSama parachains options for using Polkadot<>Kusama bridge).

Progress

• components implemented: [bridges-v2] Permissionless lanes  #4949
• Polkadot-SDK released: stable2409
• live on testnets
• integrate to fellowship/runtimes
• live on Kusama and Polkadot
• follow-ups: Bridge Permissionless Lanes - more tests #5552

Deployment plan

Bridges: Permissionless Lanes deployment doc

• [testnet bridge] Permissionless dedicated bridge lanes deployment #6116