fix(microservice): grpc-client serialize error

[gilre]

closes #10104

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Issue Number: #10104

What is the new behavior?

this.serializeError(error) is called before returning an error in client-grpc.ts,
this matches the behavior to the the rest of ClientProxy implementations

Does this PR introduce a breaking change?

• Yes
• No

Other information

I didn't find any test cases for error handling, please refer me to any if i missed it.
Added a basic test to make sure old behavior is not affected when serializeError is not overridden

[coveralls]

Pull Request Test Coverage Report for Build 110f631b-896a-4508-b96c-91951c043909

• 1 of 3 (33.33%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 93.826%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/microservices/client/client-grpc.ts	1	3	33.33%

Totals
Change from base Build 7429007a-3efb-492d-a2a1-84f706a41b5f:	0.0%
Covered Lines:	6094
Relevant Lines:	6495

---

💛 - Coveralls

[kamilmysliwiec]

LGTM