fix(frontend): uniformize case for types (#2071)

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

frontend/lib/types/BrainConfig.ts

@@ -0,0 +1,68 @@
+import { UUID } from "crypto";
+
+import { ApiBrainDefinition } from "../api/brain/types";
+
+export const brainStatuses = ["private", "public"] as const;
+
+export type BrainStatus = (typeof brainStatuses)[number];
+
+export const brainTypes = ["doc", "api", "composite"] as const;
+
+export type BrainType = (typeof brainTypes)[number];
+
+export type Model = (typeof freeModels)[number];
+
+// TODO: update this type to match the backend (antropic, openai and some other keys should be removed)
+export type BrainConfig = {
+  id: UUID;
+  model: Model;
+  temperature: number;
+  maxTokens: number;
+  keepLocal: boolean;
+  backendUrl?: string;
+  openAiKey?: string;
+  anthropicKey?: string;
+  supabaseUrl?: string;
+  supabaseKey?: string;
+  prompt_id?: string;
+  status: BrainStatus;
+  brain_type: BrainType;
+  prompt: {
+    title: string;
+    content: string;
+  };
+  name: string;
+  description: string;
+} & {
+  brain_definition?: ApiBrainDefinition;
+};
+
+export const openAiFreeModels = [
+  "gpt-3.5-turbo",
+  "gpt-3.5-turbo-1106",
+  "gpt-3.5-turbo-16k",
+] as const;
+
+export const openAiPaidModels = [...openAiFreeModels, "gpt-4"] as const;
+
+export const anthropicModels = [
+  // "claude-v1",
+  // "claude-v1.3",
+  // "claude-instant-v1-100k",
+  // "claude-instant-v1.1-100k",
+] as const;
+
+export const googleModels = [
+  //"vertexai"
+] as const; // TODO activate when not in demo mode
+
+// export const googleModels = [] as const;
+export const freeModels = [
+  ...openAiFreeModels,
+  // ...anthropicModels,
+  // ...googleModels,
+] as const;
+
+export const paidModels = [...openAiPaidModels] as const;
+
+export type PaidModels = (typeof paidModels)[number];

frontend/lib/types/Testimonial.ts

@@ -0,0 +1,8 @@
+export type Testimonial = {
+  socialMedia: "x" | "linkedin";
+  url: string;
+  jobTitle: string;
+  content: string;
+  name: string;
+  profilePicture?: string;
+};