Add integrator way to configure Solana priority fees

[tonyjin]

Description and context

Solana transactions require setting a priority fee to land transactions during periods of high congestion.

See:

• https://docs.solanalabs.com/proposals/fee_transaction_priority
• https://docs.helius.dev/solana-rpc-nodes/alpha-priority-fee-api

I propose adding a config that allows users to pass in a method for calculating appropriate Solana priority fees to set per transaction. Passing in a method allows integrators to customize how they calculate this, including:

• using Solana RPC getRecentPriorityFees to estimate based on past priority fees
• using Helius getPriorityFeeEstimate to lean on an external service to estimate appropriate priority fees

[artursapek]

I've looked into this and know generally how to get it done. however, it depends on #1698 merging first, which enables to add non-JSON-serializable things functions into the integration config. as of right now, because Connect only supports a stringified JSON config, we literally can't do this.

[tsadovska]

1. "TransactionExpiredTimeoutError" appears in Console when sending assets from Solana. Checked on https://wormhole-connect-mainnet.netlify.app/ [Mainnet] and https://preview.portalbridge.com/b1ba6e856a/ [Mainnet]. Ticket [QA] [Mainnet] Transactions from Solana fails with "TransactionExpiredTimeoutError" error #1689.

2. "TransactionExpiredBlockheightExceededError" appears in Console when sending assets to Solana. Checked on https://wormhole-connect-mainnet.netlify.app/ [Mainnet] and https://preview.portalbridge.com/b1ba6e856a/ [Mainnet]. Ticket [QA] "TransactionExpiredBlockheightExceededError" when claiming on Solana #1754.