Added duplicate name check logic when registering a candidate

[Zena-park]

• When registering RollupConfig in L1BridgeRegistry, the name is also registered.

• When registering a candidate through Layer2Manger, the RollupConfig registered in L1BridgeRegistry must have the same name.

• Duplicate names are not allowed.

[Zena-park]

test: prevent duplicate names Adding the name when registering rollupConfig, test to prevent duplicate names

https://github.com/tokamak-network/ton-staking-v2/commit/baf931c7134c45f7bca8bed7181fa2900d931199

[Zena-park]

feat: Add a name when registering rollupConfig

• Add a name when registering rollupConfig
• Modify logic to prevent registration of duplicate names

https://github.com/tokamak-network/ton-staking-v2/commit/c228611630a91e8ea26d0b1b7664248dd2bfe22a