Bridge UI optimization - Githubissues

[x] Change all 'Optimism' to 'Mantle Network'
[x] Delete optimism & op goerli from the network list, add Mantle Testnet
[x] Change the UI color according to mantle bridge figma files https://www.figma.com/file/3o1eXRxwOG3sexYdDf2KRF/Mentle-%E6%95%B0%E6%8D%AE%E5%AE%98%E7%BD%91?node-id=0%3A1&t=4oP7hCfs1WGTHgjh-0
[x] Delete 'Fiat on Ramp‘ & ’Exchanges' from the deposit network list, leave only Goerli
[x] Fix the bug that can't switch the network to Mantle Testnet when withdraw token from l2 to l1
[x] Rename 'Bitnetwork‘ to 'Mantle Testnet'
[x] Change the 'Time to transfer' on the withdraw interface to 5 minutes
[x] Change op explorer to mantle testnet explorer in the account details page
[x] Delete 'Routing' on the confirm deposit pop-up window
[x] Change 'optimism' on the deposit hover window to 'Mantle'
[x] Change the webpage title to 'Mantle Bridge'
[ ] Hint the button 'Explore apps on Mantle'

mantlenetworkio / mantle