Protected packages: Validate package_name_pattern format

What does this MR do and why?

• During a MR review, we noticed that npm packages only allow a certain format for the package name, e.g. no backslashes characters, no asterisk characters, etc.
• When implementing package protection rule for npm packages, the field package_name_pattern should also consider the format validation that is applied to npm packages => This MR wants to add this format validation.

🛠 with ❤ at Siemens

Screenshots or screen recordings

This MR has no frontend changes.

How to set up and validate locally

1. Create a valid package protection rule because the field package_name_pattern is

package = Packages::Package.new(project: Project.find(7), name: "@gitlab-org/npm-package-valid-name")
package.valid? # => true

package_protection_rule = Packages::Protection::Rule.new(project: Project.find(7), package_type: :npm, push_protected_up_to_access_level: Gitlab::Access::DEVELOPER, package_name_pattern: "@gitlab-org/npm-package-valid-name")
package_protection_rule.valid? # => true

2. Create an invalid package protection rule because the field package_name_pattern cannot represent a valid package name

package = Packages::Package.new(project: Project.find(7), name: "@gitlab-org/npm-package-%%")
package.valid? # => false
package.errors.full_messages # => ["Name is invalid"]

package_protection_rule = Packages::Protection::Rule.new(project: Project.find(7), package_type: :npm, push_protected_up_to_access_level: Gitlab::Access::DEVELOPER, package_name_pattern: "@gitlab-org/npm-package-%%")
package_protection_rule.valid? # => false
package_protection_rule.errors.full_messages # => ["Package name pattern should be a valid NPM package name with optional wildcard characters."]

Todos

• @gerardo-navarro Finish the description of the MR

MR acceptance checklist

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