Electra: Rename objects with prefix ExecutionLayerXXX

[prestonvanloon]

Rationale:

Following #3757, which renames from DepositReceipt to DepositRequest to conform with the patterns in EIP-7685, this PR aims to have further conformity by dropping the ExecutionLayer prefix from WithdrawalRequest and ConsolidationRequest.

Changes:

• Rename ExecutionLayerWithdrawalRequest->WithdrawalRequest
• Rename ExecutionLayerConsolidationRequest->ConsolidationRequest
• Rename process_execution_layer_withdrawal_request->process_withdrawal_request
• Rename process_execution_layer_consolidation_request->process_consolidation_request
• Rename variable/argument execution_layer_withdrawal_request->withdrawal_request
• Rename variable/argument execution_layer_consolidation_request->consolidation_request

[mkalinin]

The proposed renaming makes sense to me as having both ExecutionLayer prefix and Request suffix looks redundant from my perspective

[hwwhww]

I like this clean-up! Hope to see more support (approvals/👍) before merging it.