A read-scoped project key, so a Stacks dashboard can read logs without a person's credentials

• 2aaf777911 feat(api): a read-scoped project key, so a machine can read logs without a person's credentials glennmichael123 review this step
• abed4b7524 feat(settings): issue and revoke a project's read key glennmichael123 review this step
• 1145eb5aad fix: narrow the read-key row, and drop em-dashes from the key's copy glennmichael123 review this step
• 126dc1ba36 fix(settings): keep the read key's server values out of the signal names glennmichael123 review this step