Bugzilla

Along with the ongoing work for the new implementation based on a separate AddonManager Provider meant to only manage the Site Permissions addon type (Bug 1778959) we need to prepare to remove the initial XPIProvider based one (introduced by Bug 1737163).

As a side note to keep in mind while we are planning the removal:

- The XPIProvider-based implementation recognize an xpi as add-on type "sitepermission"  based on the presence of the top level manifest key "sitepermissions" otherwise fallback to "extensions" (see [ExtensionData initializeAddonTypeAndID method](https://searchfox.org/mozilla-central/rev/2d65dbd85ca11309dc0c485a63393110ef800083/toolkit/components/extensions/Extension.jsm#1186-1190))

- The ExtensionBlocklistMLBF defined in Blocklist.jsm determines which addon type should be checked by the addon blocklist based on the types exported by the XPIProvider (see [kXPIAddonType lazy getter defined in Blocklist.jsm here](https://searchfox.org/mozilla-central/rev/2d65dbd85ca11309dc0c485a63393110ef800083/toolkit/mozapps/extensions/Blocklist.jsm#86-95)), if the new implementation lands before we have removed the XPIProvider implementation this may be a part that we may split off into its own separate bugzilla issue and cover it in the same release where the new implementation is landing

Along with the ongoing work for the new implementation based on a separate AddonManager Provider meant to only manage the Site Permissions addon type (Bug 1778959) we need to prepare to remove the initial XPIProvider based one (introduced by Bug 1737163).

As a side note to keep in mind while we are planning the removal:

- The XPIProvider-based implementation recognize an xpi as add-on type "sitepermission"  based on the presence of the top level manifest key "site_permissions" otherwise fallback to "extensions" (see [ExtensionData initializeAddonTypeAndID method](https://searchfox.org/mozilla-central/rev/2d65dbd85ca11309dc0c485a63393110ef800083/toolkit/components/extensions/Extension.jsm#1186-1190))

- The ExtensionBlocklistMLBF defined in Blocklist.jsm determines which addon type should be checked by the addon blocklist based on the types exported by the XPIProvider (see [kXPIAddonType lazy getter defined in Blocklist.jsm here](https://searchfox.org/mozilla-central/rev/2d65dbd85ca11309dc0c485a63393110ef800083/toolkit/mozapps/extensions/Blocklist.jsm#86-95)), if the new implementation lands before we have removed the XPIProvider implementation this may be a part that we may split off into its own separate bugzilla issue and cover it in the same release where the new implementation is landing