MM-17023: Plugin Marketplace (#12183)

* MM-17149 - Extend config.json for marketplace settings (#11933)

* MM-17149 - Extend config.json for marketplace settings

* Renamed MarketplaceUrl, tracking default marketplace url

* Added EnableMarketplace to the client config

* Revert "Added EnableMarketplace to the client config"

This reverts commit 0f982c4c661c2cd9bb96264e9a01a2363c40d9c5.

* MM-17149 - Added EnableMarketplace to the client config (#11958)

* Added EnableMarketplace to the client config

* Moved EnableMarketplace setting out of limited client configuration

* MM-17150, MM-17545, MM-18100 - Implement GET /api/v4/plugins/m… (#11977)

* MM-17150 - Implement GET /api/v4/plugins/marketplace proxying upstream
MM-17545 - Merge locally installed plugins into GET /api/v4/plugins/marketplace

* Replaced MarketplacePluginState with Installed

* Setting InstalledVersion instead of Installed

* marketplace client setting per_page if non zero

* Creating insecure client for marketplace url

* Fixed trailing slash for default marketplace url

* Adding filtering

* Fixed function names

* Renamed Manifest() to GetManifest(), added godoc for BaseMarketplacePlugin

* Handling plugin.ErrNotFound correctly

* Checking err == nil instead when a plugin is installed

* MM-18450 - Local-only plugin search (#12152)

* MM-17846: plugin icons (#12157)

* MM-17846: add support for plugin icons

Extend the model definitions to support plugin icons from the marketplace.

* s/IconURL/IconData

* MM-18475 - Converge on snake_case responses from the marketplace (#12179)

* MM-18520 - MM-Server should forward server version to marketplace server (#12181)

* Renamed request to filter client4.GetMarketplacePlugins

* Renamed request to filter

* Guarding against bad marketplace server response

model/client4.go

@@ -4519,6 +4519,31 @@ func (c *Client4) DisablePlugin(id string) (bool, *Response) {
 	return CheckStatusOK(r), BuildResponse(r)
 }
 
+// GetMarketplacePlugins will return a list of plugins that an admin can install.
+// WARNING: PLUGINS ARE STILL EXPERIMENTAL. THIS FUNCTION IS SUBJECT TO CHANGE.
+func (c *Client4) GetMarketplacePlugins(filter *MarketplacePluginFilter) ([]*MarketplacePlugin, *Response) {
+	route := c.GetPluginsRoute() + "/marketplace"
+	u, parseErr := url.Parse(route)
+	if parseErr != nil {
+		return nil, &Response{Error: NewAppError("GetMarketplacePlugins", "model.client.parse_plugins.app_error", nil, parseErr.Error(), http.StatusBadRequest)}
+	}
+
+	filter.ApplyToURL(u)
+
+	r, err := c.DoApiGet(u.String(), "")
+	if err != nil {
+		return nil, BuildErrorResponse(r, err)
+	}
+	defer closeBody(r)
+
+	plugins, readerErr := MarketplacePluginsFromReader(r.Body)
+	if readerErr != nil {
+		return nil, BuildErrorResponse(r, NewAppError(route, "model.client.parse_plugins.app_error", nil, err.Error(), http.StatusBadRequest))
+	}
+
+	return plugins, BuildResponse(r)
+}
+
 // UpdateChannelScheme will update a channel's scheme.
 func (c *Client4) UpdateChannelScheme(channelId, schemeId string) (bool, *Response) {
 	sip := &SchemeIDPatch{SchemeID: &schemeId}