feat: add access control to pushCertificate

[JDawg287]

Description

This PR adds an access control modifier to the pushCertificate method of the ToposCore.sol smart contract. That is to prevent external access for the time being.
In order to isolate the constant deployment account from the admin (sequencer) of the ToposCore.sol contract, this PR also adds an initialize function to the ToposCore.sol contract.

Fixes TP-656

Additions and Changes

• Added onlyAdmin modifier for the pushCertificate method
• Added initialize function in the ToposCore.sol contract
• Removed the setup function in the ToposCore.sol contract as it is no longer required
• Removed the initial arguments for the setup in the ToposCoreProxy.sol contract
• Added unit test to test the functionality

PR Checklist:

• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works

[hadjiszs]

ah I think the Sequencer test doesn't pass anymore because it can't call the pushCertificate as it needs to be added as admin then

cc @atanmarko

[sebastiendan]

ah I think the Sequencer test doesn't pass anymore because it can't call the pushCertificate as it needs to be added as admin then

cc @atanmarko

I was waiting for the test to pass to review. @JDawg287 ping me when everything passes!

[JDawg287]

@sebastiendan The e2e tests are working!
@atanmarko We just need to change a bit again for the sequencer tests.