feat(microservices): Allow RegExps in Patterns for Kafka

[edeesis]

closes #3083

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?

RegExps could be added and the Typescript would compile, but at runtime, you'd get an error:

The request attempted to perform an operation on an invalid topic
KafkaJSProtocolError: The request attempted to perform an operation on an invalid topic

because normalizePattern in Server.ts would map a RegExp to the string "{}"

Issue Number: #3083

What is the new behavior?

Now RegExp is allowed for Kafka, and the same handler can be used for multiple topics that match the pattern.

Does this PR introduce a breaking change?

• Yes
• No

Other information

N/A

[coveralls]

Pull Request Test Coverage Report for Build 1655e549-2fd5-4751-b8c6-c46ec218cd58

Details

• 2 of 4 (50.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.03%) to 92.098%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/microservices/server/server-kafka.ts	2	4	50.0%

Totals
Change from base Build 5c503562-0bb3-4aab-98b2-462ef8204cb2:	-0.03%
Covered Lines:	6737
Relevant Lines:	7315

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💛 - Coveralls

[edeesis]

Closing for rework