Assign ownership to many libs files (#6928)

Assign ownership to many of the remaining libs/common files.

Criteria for ownership:
* Files used by a single team, is now owned by that team.
* Files related to a domain owned by a team is now owned by that team.
* Where ownership is unclear the "lowest level" service takes ownership.

libs/angular/src/platform/services/theming/theme-builder.ts

@@ -0,0 +1,19 @@
+import { ThemeType } from "@bitwarden/common/platform/enums";
+
+import { Theme } from "./theme";
+
+export class ThemeBuilder implements Theme {
+  get effectiveTheme(): ThemeType {
+    return this.configuredTheme != ThemeType.System ? this.configuredTheme : this.systemTheme;
+  }
+
+  constructor(readonly configuredTheme: ThemeType, readonly systemTheme: ThemeType) {}
+
+  updateSystemTheme(systemTheme: ThemeType): ThemeBuilder {
+    return new ThemeBuilder(this.configuredTheme, systemTheme);
+  }
+
+  updateConfiguredTheme(configuredTheme: ThemeType): ThemeBuilder {
+    return new ThemeBuilder(configuredTheme, this.systemTheme);
+  }
+}