Improve rancher performance by updating Extensions to be inline with server-side pagination

[richard-cox]

Many extensions will fetch all of a resource type anyway, negating and making the performance worse in SSP world. For example if a user flicks between the cluster configmap list (fetch a page) and a kw page where all config maps are fetched, each indivual visit will clear the cache and make a new request (can be costly when fetching all)

Extensions can also gain the benefit of SSP performance bump

Issues to be created in extension specific repos

• Improve Fleet performance (server-side pagination, remove findAlls)
• [ENHANCEMENT] Improve Harvester UI Extension Performance (placeholder) harvester/harvester#7342
• Improve KubeWarden performance (server-side pagination, remove findAlls)
• Improve Elemental performance (server-side pagination, remove findAlls)
• Improve NeuVector performance (server-side pagination, remove findAlls)
• Improve StackState performance (server-side pagination, remove findAlls)
• Other Rancher Extensions?