Rename SetPreSignatureDecoder and usage to GPv2Decoder

[iamacook]

Summary

We will need to debug more methods on the GPv2Settlement contract for #1650 and therefore create relevant decoders for. Currently, we have a SetPreSignatureDecoder which specifically interacts with this contract.

This renames it and usage of it to GPv2Decoder, which also matches the style across the project for other decoders.

[coveralls]

Pull Request Test Coverage Report for Build 9566991952

Details

• 9 of 13 (69.23%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 49.406%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/routes/transactions/helpers/swap-order.helper.ts	2	3	66.67%
src/routes/transactions/mappers/common/swap-order.mapper.ts	2	3	66.67%
src/routes/transactions/transactions-view.service.ts	1	3	33.33%

Totals
Change from base Build 9563691273:	0.0%
Covered Lines:	3971
Relevant Lines:	6464

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9568438597

Details

• 9 of 13 (69.23%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.05%) to 49.451%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/routes/transactions/helpers/swap-order.helper.ts	2	3	66.67%
src/routes/transactions/mappers/common/swap-order.mapper.ts	2	3	66.67%
src/routes/transactions/transactions-view.service.ts	1	3	33.33%

Totals
Change from base Build 9563691273:	0.05%
Covered Lines:	3973
Relevant Lines:	6464

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9578954443

Details

• 9 of 13 (69.23%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 49.274%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/routes/transactions/helpers/swap-order.helper.ts	2	3	66.67%
src/routes/transactions/mappers/common/swap-order.mapper.ts	2	3	66.67%
src/routes/transactions/transactions-view.service.ts	1	3	33.33%

Totals
Change from base Build 9578682874:	0.0%
Covered Lines:	4068
Relevant Lines:	6658

---

💛 - Coveralls