* seal: Change prefix "ext_" to "seal_" for contract callable functions
The word Ext is a overloaded term in the context of substrate. It usually
is a trait which abstracts away access to external resources usually in order
to mock them away for the purpose of tests. The contract module has its own
`Ext` trait in addition the the substrate `Ext` which makes things even more
confusing.
In order to differentiate the contract callable functions more clearly from
this `Ext` concept we rename them to use the "seal_" prefix instead.
This should change no behaviour at all. This is a pure renaming commit.
* seal: Rename import module from "env" to "seal0"
* seal: Fixup integration test
* seal: Add more tests for new import module names
* Transition getter functions to not use scratch buffer
* Remove scratch buffer from ext_get_storage
* Remove scratch buffer from ext_call
* Remove scratch buffer from ext_instantiate
* Add ext_input and remove scratch buffer
* Rework error handling (changes RPC exposed data)
* ext_return passes a flags field instead of a return code
* Flags is only for seal and not for the caller
* flags: u32 replaced status_code: u8 in RPC exposed type
* API functions use a unified error type (ReturnCode)
* ext_transfer now traps on error to be consistent with call and instantiate
* Remove the no longer used `Dispatched` event
* Updated inline documentation
* Prevent skipping of copying the output for getter API
* Return gas_consumed from the RPC contracts call interface
* Updated COMPLEXTITY.md
* Rename ext_gas_price to ext_weight_to_fee
* Align comments with spaces
* Removed no longer used `ExecError`
* Remove possible panic in `from_typed_value`
* Use a struct as associated data for SpecialTrap::Return
* Fix nits in COMPLEXITY.md
* Renamed SpecialTrap to TrapReason
* Fix test
* Finish renaming special_trap -> trap_reason
* Remove no longer used get_runtime_storage
* fixup! Remove no longer used get_runtime_storage
* Removed tabs for comment aligment
Alexander Theißen