vms/platformvm: configure state cache sizes #1522

[najeal]

Why this should be merged

It resolves and close #1522

How this works

It defines an execution config used to configure platformvm state cache size.
A default config is used and overridden by configBytes arg in the Initialize() function of the VM.

How this was tested

Unit test of the default config and the override of the values.

[abi87]

some nits and a couple of major requests (repackage execConfig + move trackChecksum in). Overall very helpful cleanup. Thanks @najeal!

[abi87]

@najeal a couple of nits, then it's good to me. I'll approve as soon as you fix them

[najeal]

@abi87 I have seen all json configs in the project are camelCase. So the created config has camelCase keys except the ChecksumsEnabled because I would potentially break something...
It's not consistent but I have no choice.

By the way if you have others issues for new comers don't hesitate to mention me.

[abi87]

@abi87 I have seen all json configs in the project are camelCase. So the created config has camelCase keys except the ChecksumsEnabled because I would potentially break something... It's not consistent but I have no choice.

By the way if you have others issues for new comers don't hesitate to mention me.

I am sure you alread looked at the good first issues. Will check if there other outstanding ones and duly tag them. Thanks for your contribution @najeal

[najeal]

@abi87 yes I did :)

[StephenButtolph]

Just 2 last super small nits then LGTM. Sorry for the long turn-around on these reviews