[IDP-1218] add a custom user agent header to the mfa client

[briskt]

IDP-1218 Configure Cloudflare so our MFA is 'known' and not blocked with certain bot settings

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Added

• Added a User-Agent header to the MFA client. This may help id-broker look less like a bot to Cloudflare, or at least make it possible to register it as acceptable.

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Feature PR Checklist

• [ ] Documentation (README, local.env.dist, api.raml, etc.)
• [ ] Tests created or updated
• [ ] Run make composershow
• [x] Run make psr2

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud