[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>

web/source/css/base.css

@@ -599,7 +599,7 @@ section.oob-token {
 	}
 }
 
-.domain-blocklist {
+.domain-perm-list {
 	box-shadow: $boxshadow;
 
 	.entry {
@@ -632,7 +632,7 @@ section.oob-token {
 }
 
 @media screen and (max-width: 30rem) {
-	.domain-blocklist .entry {
+	.domain-perm-list .entry {
 		grid-template-columns: 1fr;
 		gap: 0;
 	}