PlatformProxyAdmin deployer constant concerns

[georgercarder]

The code4rena issue https://github.com/code-423n4/2022-05-enso-findings/issues/217 raises that the deployer constant is "useless" since the inherited ProxyAdmin is ownable, thus the initialize function could be modified to be callable only by the owner.

If the intended design of deployer was to accommodate the PlatformProxyAdmin itself to be proxied, than the owner credentials would be lost, bricking the ProxyAdmin onlyOwner controlled functions. So as it is set up, the PlatformProxyAdmin should NOT be proxied.

So far during the code4rena engagement there have been no other changes to the PlatformProxyAdmin so it would not need to be redeployed. This means it would not make sense to remove this "useless" constant.

label "tracking" used since there is no actionable item on this issue other than consideration and possibly revisiting in the future.