Use externalInfoUrl for custom rules

[nicolas1bruno]

Is your feature request related to a problem? Please describe.
When running Apex PMD with a custom ruleset, with custom rules in it, the url provided in the problems tab is invalid

Describe the solution you'd like
The Apex PMD extension should prioritize the URL provided in the externalInfoUrl, available on the ruleset schema

Additional context
In the current version the url is hard-coded, see ApexPmd.ts#L241

vscode-apex-pmd/src/lib/apexPmd.ts

Lines 241 to 244 in 74ec3e5

	const uri = `https://pmd.github.io/latest/pmd_rules_apex_${result.ruleSet
	.split(' ')
	.join('')
	.toLowerCase()}.html#${result.rule.toLowerCase()}`;

[NickTracker]

I also have this need, thanks for opening