[feature] Allow exposing allows, implement /api/v1/domain_blocks and /api/v1/domain_allows (#4169)

- adds config flags `instance-expose-allowlist` and `instance-expose-allowlist-web` to allow instance admins to expose their allowlist via the web + api.
- renames `instance-expose-suspended` and `instance-expose-suspended-web` to  `instance-expose-blocklist` and `instance-expose-blocklist-web`.
- deprecates the `suspended` filter on `/api/v1/instance/peers` endpoint and adds `blocked` and `allowed` filters
- adds the `flat` query param to `/api/v1/instance/peers` to allow forcing return of a flat list of domains
- implements `/api/v1/instance/domain_blocks` and `/api/v1/instance/domain_allows` endpoints with or without auth depending on config
- rejigs the instance about page to include a general section on domain permissions, with block and allow subsections (and appropriate links)

Closes https://codeberg.org/superseriousbusiness/gotosocial/issues/3847
Closes https://codeberg.org/superseriousbusiness/gotosocial/issues/4150

Prerequisite to https://codeberg.org/superseriousbusiness/gotosocial/issues/3711

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4169
Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Co-committed-by: tobi <tobi.smethurst@protonmail.com>

internal/web/about.go

@@ -57,7 +57,8 @@ func (m *Module) aboutGETHandler(c *gin.Context) {
 		Stylesheets: []string{cssAbout},
 		Extra: map[string]any{
 			"showStrap":        true,
-			"blocklistExposed": config.GetInstanceExposeSuspendedWeb(),
+			"blocklistExposed": config.GetInstanceExposeBlocklistWeb(),
+			"allowlistExposed": config.GetInstanceExposeAllowlistWeb(),
 			"languages":        config.GetInstanceLanguages().DisplayStrs(),
 		},
 	}