fix: Flaky tests

[yagopv]

What it solves

Resolves https://github.com/safe-global/safe-core-sdk/issues/827

How this PR resolves it

• The api-kit test was failing because it was relying on the length of the results array instead of using the count property value. From 100 items, the call is automatically paginated, so count should always be used for these types of comparisons

• A cache has been added in the Safe4337Pack instantiation, as the protocol-kit initialization takes time, and most of the instances can be reused

• The timeout has been increased

[coveralls]

Pull Request Test Coverage Report for Build 9271294912

Details

• 6 of 6 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 77.907%

---

Totals
Change from base Build 9265754477:	0.1%
Covered Lines:	736
Relevant Lines:	880

---

💛 - Coveralls