feat(themes): Support naming themes

Currently themes don't have names, and it's better to have a way to attach a name to a theme. So that we can know about theme without having to look at the theme data.
<think>
PR Context:
- Title: feat(themes): Add `theme_name` and `entity_type` in themes table
- Merged: 2024-11-21T21:06:12Z
- Files changed: 8 files
- Commits: 1 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [x] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
This PR adds `theme_name` and `entity_type` in the themes table.
This will help us in 
1. Having a name for the theme.
2. EntityType identifier to help us identity the lineage type instead of guessing it.

### Additional Changes

- [ ] 
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(themes): Add `theme_name` and `entity_type` in themes table (#6621)
Files to modify:


**crates/common_utils/src/types/theme.rs**
  Modify existing code

**crates/diesel_models/src/query/user/theme.rs**
  Modify existing code

**crates/diesel_models/src/schema.rs**
  Modify existing code

**crates/diesel_models/src/schema_v2.rs**
  Modify existing code

**crates/diesel_models/src/user/theme.rs**
  Modify existing code

**crates/router/src/db/user/theme.rs**
  Modify existing code
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