[ink_e2e] improve call API, remove build_message + callback

[ascjones]

Resurrecting the idea from #1669.

I believe it closes #1644, since the main thing is removing that ugly callback. This may not be the fina or most sophisticatedl API, but an increment in the right direction for better quality of life for e2e test devs.

Replaces build_message and callback with a simpler:

            let erc20 = client
                .instantiate("erc20", &ink_e2e::alice(), constructor, 0, None)
                .await
                .expect("instantiate failed");
            let mut call = erc20.call::<Erc20>();

            // dry run
            let total_supply_msg = call.total_supply();
            let total_supply_res = client
                .call_dry_run(&ink_e2e::bob(), &total_supply_msg, 0, None)
                .await;

            // tx
            let transfer_from =
                call.transfer_from(bob_account.clone(), charlie_account.clone(), amount);
            let transfer_from_result = client
                .call(&ink_e2e::charlie(), &transfer_from, 0, None)
                .await;

[cmichi]

Thanks for doing this!

We should reflect the change in a CHANGELOG.md. Since we so far always released in lockstep with the rest of ink!, I would just add it there for now.

[codecov-commenter]

Codecov Report

Merging #1782 (5087d30) into master (49bd8d3) will decrease coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1782      +/-   ##
==========================================
- Coverage   52.09%   52.05%   -0.05%     
==========================================
  Files         207      207              
  Lines        6653     6653              
==========================================
- Hits         3466     3463       -3     
- Misses       3187     3190       +3     

Impacted Files	Coverage Δ
crates/e2e/src/client.rs	0.00% <ø> (ø)
crates/e2e/src/lib.rs	0.00% <ø> (ø)
crates/e2e/src/xts.rs	0.00% <ø> (ø)
crates/env/src/call/call_builder.rs	0.00% <ø> (ø)
crates/env/src/call/execution_input.rs	76.31% <ø> (ø)

... and 2 files with indirect coverage changes

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