Add upfront grant to Smart Escrow

[anikaraghu]

Before we were going to handle the upfront grant tokens separately, because we wanted to delegate these and start voting before the 1 year cliff. However, given the 1 year cliff is approaching and some product changes impacting the ability to partially delegate, we'll have both upfront and collab grant tokens handled via the smart escrow. The only material change to the contract is that there is an additional 10,737,418 OP that should vest upon the cliff (ie part of "initialTokens"). Making this part of the same task rather than a new one just so reviewers can easily see the diff

Note that we made a small change to the contract which was to remove the Start time not in the past check (since this time is now in fact in the past). This is reflected here: https://github.com/base-org/contracts/pull/89 and does not have any material change on the contract

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1