refactor: Lint for no unneeded backticks

[ivov]

Wrote tests for this but the RuleTester parser seemingly chokes on backticks, whether escaped on not.

ruleTester.run('no-unneeded-backticks', rules['no-unneeded-backticks'], {
	valid: [
		{
			code: "var str = 'abc';",
		},
		{
			code: 'var str = "abc";',
		},
		{
			code: `
				This is a sentence.
				This is another.
			`,
		},
		{
			code: `This is a \${myVar}`,
		},
	],
	invalid: [
		{
			code: 'var str = \\`abc\\`;',
			errors: [{ messageId: 'noUnnededBackticks' }],
			output: "var str = 'abc';",
		},
		{
			code: "var str = `abc 'def' ghi`;",
			errors: [{ messageId: 'noUnnededBackticks' }],
			output: 'var str = \'abc "def" ghi\';',
		},
	],
});

[netroy]

Looks good.
Can we please also add another rule to enforce backticks when there is a ${...} token present?

[janober]

Got released with [email protected]