Add routeEnum with validation and enhance error handling in BaseService [Twitter Gem TeamCity Packagist MozillaObservatory HexPm Greasyfork]

[jNullj]

A step towards #11371 and express.js

some impotent points:

1. We can't use enum in route anymore in future versions of dependencies, this is a refactor is part 1 to solve this
2. i tried to get the most elegant and efficient solution at the cost of flexibility
3. the code assumes and limits enum only the first param, i couldn't find any services with multiple enum params and non first param as enum, it also makes semse
4. if any exception arise, we can always solve them at handle()
5. i could make a multi param system but it would be more costly in run-time then a single include check in an array.
6. this will require many follow up PR for all services...

[github-actions]

	Warnings
⚠️	This PR modified service code for gem but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for greasyfork but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for hexpm but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for mozilla-observatory but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for packagist but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for teamcity but not its test code. That's okay so long as it's refactoring existing code.
⚠️	This PR modified service code for twitter but not its test code. That's okay so long as it's refactoring existing code.
⚠️	Found badge URL that may not follow our standard route abbreviations in services/gem/gem-downloads.service.js. Please ensure you've reviewed our conventions.

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