Chainspec wasm configuration doesn't allow defining different costs for different VMs

[zajko]

Currently the cost properties look like:

[wasm.host_function_costs]
add = { cost = 5_800, arguments = [0, 0, 0, 0] }
add_associated_key = { cost = 1_200_000, arguments = [0, 0, 0] }
add_contract_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 0, 0] }
add_package_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 30_000, 0, 0] }
[wasm.opcode_costs.*]

This gives us no possibility of differentiating between costs for different virtual machines. Also, it would be hard to support a different set of host functions for different VMs
We want the structure to be like:

[wasm.v1.host_function_costs]
add = { cost = 5_800, arguments = [0, 0, 0, 0] }
add_associated_key = { cost = 1_200_000, arguments = [0, 0, 0] }
add_contract_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 0, 0] }
add_package_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 30_000, 0, 0] }
[wasm.v1.opcode_costs.*]

[wasm.v2.host_function_costs]
add = { cost = 5_800, arguments = [0, 0, 0, 0] }
add_associated_key = { cost = 1_200_000, arguments = [0, 0, 0] }
add_contract_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 0, 0] }
add_package_version = { cost = 200, arguments = [0, 0, 0, 0, 120_000, 0, 0, 0, 30_000, 0, 0] }
[wasm.v2.opcode_costs.*]

Additionally, promote the [wasm.storage_costs] to a root level property ([storage_costs])