Copy the `Transaction` to the Wasm Instance Memory

[Yaron Wittenstein]

Depends on: #456 #457 #460 #461

As things stand now, the Runtime takes the relevant calldata piece of the transaction and it copies only it to the Wasm Instance Memory before running it.

• If the function to run is verify (svm_verify if to be precise) then the calldata piece will be the verifydata field given in the Transaction
  

  svm/crates/runtime/src/runtime/runtime.rs

  Line 655 in 6edb73d

   tx.verifydata(), 

• If the function to run is the ctor for a Spawn Transaction then the calldata will be the ctordata field given:
  

  svm/crates/runtime/src/runtime/runtime.rs

  Line 53 in 6edb73d

   func_input: spawn.ctor_data(), 

maybe better to rename: ctor_data to ctordata

• If the function to run is "the function" of a Call Transaction then the calldata should be the funcdata field given
  (see issue #461)

svm/crates/runtime/src/runtime/runtime.rs

Line 676 in 6edb73d

 tx.calldata(), 

This issue wants to achieve two things:

• Have the binary Transaction copied to the Instance Memory
• Avoid copying the calldata separately since this data is already parts of the Transaction (it's just that the field holding that data is contextual to the running code).

Implementation Proposal

Update the Call struct (see also #458)

Since this issue depends on #456 we should have now the binary transaction accessible within the FuncEnv.

The run method in the Runtime is a lower-level abstraction that will execute code.
Each execution will end up calling this function for running:

svm/crates/runtime/src/runtime/runtime.rs

Line 104 in 6edb73d

 fn run<Args, Rets>( 

It seems that if we'll update the Call struct (might have a different name by now - see #458)
https://github.com/spacemeshos/svm/blob/6edb73de199fafce0953f82af061ca1090ff911c/crates/runtime/src/runtime/call.rs

to be like:

// `Call` might have been renamed by now
#[derive(Debug, Clone, PartialEq)]
pub struct Call {
  // It's enough to just specify what the `calldata` means,
  // we don't need the `func_input` anymore.
  pub kind: TxPart, 
}

Since the calldata is held in the binary Transaction we can manage by just specifying that the Call is for executing a verify/ctor/call tx function. If we decide to have also authorize then it'd be easy to adapt.

Adapt how the calldata offsets are extracted

TBD