feat(frontend): replace placeholder avatar with identicons

i don't actually know what the license on the kitten image is, and while
it's very unlikely, i don't want to get into legal trouble. it was only
ever supposed to be a temporary image, too.

identicons aren't the prettiest but at least they have a clear license
:3

Foxnouns.Frontend/src/routes/settings/+page.svelte

@@ -55,6 +55,7 @@
 	<div class="col-md-3 text-center">
 		<h5>{$t("settings.avatar")}</h5>
 		<Avatar
+			name={data.user.username}
 			url={data.user.avatar_url}
 			alt={$t("avatar-tooltip", { name: "@" + data.user.username })}
 		/>

Foxnouns.Frontend/src/routes/settings/members/+page.svelte

@@ -30,6 +30,7 @@
 	{#each data.members as member (member.id)}
 		<ListGroupItem tag="a" href="/settings/members/{member.id}" data-sveltekit-preload-data="tap">
 			<Avatar
+				name={member.name}
 				url={member.avatar_url}
 				alt={$t("avatar-tooltip", { name: member.display_name })}
 				size={20}

Foxnouns.Frontend/src/routes/settings/members/[id]/+page.svelte

@@ -74,6 +74,7 @@
 	<div class="col-md">
 		<h4>{$t("settings.avatar")}</h4>
 		<AvatarEditor
+			name={data.member.name}
 			current={data.member.avatar_url}
 			alt={$t("avatar-tooltip", { name: data.member.name })}
 			update={updateAvatar}

Foxnouns.Frontend/src/routes/settings/profile/+page.svelte

@@ -91,6 +91,7 @@
 	<div class="col-md">
 		<h4>{$t("settings.avatar")}</h4>
 		<AvatarEditor
+			name={data.user.username}
 			current={data.user.avatar_url}
 			alt={$t("avatar-tooltip", { name: "@" + data.user.username })}
 			update={updateAvatar}