Add Linea L2

[jmederosalvarado]

Changes

• Adds chainspec and configs for Linea L2

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Description

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Notes on testing

Need to sync a few times to make sure everything works as expected

Documentation

Requires documentation update

• Yes
• No

If yes, link the PR to the docs update or the issue with the details labeled docs. Remove if not applicable.

Requires explanation in Release Notes

• Yes
• No

If yes, fill in the details here. Remove if not applicable.

Remarks

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[kamilchodola]

General comment:
Shouldn't each new config have default name for Metrics?
Like:
"Metrics": {
"NodeName": "Energy_Web"
},

?