feat: add contact filter for conversations (#14629)

# Pull Request Template

## Description

Adds a Contact condition to the conversation advanced filter so agents
can search for an existing contact and filter conversations by
`conversations.contact_id`.

Fixes
[CW-7239](https://linear.app/chatwoot/issue/CW-7239/contact-filter-for-conversations)

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality not to work as expected)
- [ ] This change requires a documentation update

## How Has This Been Tested?

- `eval "$(rbenv init -)" && bundle exec rspec
spec/services/conversations/filter_service_spec.rb`
- `pnpm exec vitest --no-watch --no-cache --no-coverage --logHeapUsage
app/javascript/dashboard/components-next/filter/helper/filterHelper.spec.js
app/javascript/dashboard/store/modules/conversations/helpers/specs/filterHelpers.spec.js
app/javascript/dashboard/helper/specs/customViewsHelper.spec.js
app/javascript/dashboard/helper/specs/filterQueryGenerator.spec.js`
- `pnpm eslint`
- `eval "$(rbenv init -)" && bundle exec rubocop
spec/services/conversations/filter_service_spec.rb`

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

app/javascript/dashboard/helper/customViewsHelper.js

@@ -37,6 +37,13 @@ export const getValuesName = (values, list, idKey, nameKey) => {
   };
 };
 
+const getValuesForContact = (values, contacts) => ({
+  id: values[0],
+  name:
+    contacts?.find(contact => contact.id === values[0])?.name ||
+    `Contact #${values[0]}`,
+});
+
 export const getValuesForStatus = values => {
   return values.map(value => ({ id: value, name: value }));
 };
@@ -84,6 +91,7 @@ export const getValuesForFilter = (filter, params) => {
     campaigns,
     labels,
     priority,
+    contacts,
   } = params;
   switch (attribute_key) {
     case 'status':
@@ -94,6 +102,8 @@ export const getValuesForFilter = (filter, params) => {
       return getValuesName(values, inboxes, 'id', 'name');
     case 'team_id':
       return getValuesName(values, teams, 'id', 'name');
+    case 'contact_id':
+      return getValuesForContact(values, contacts);
     case 'campaign_id':
       return getValuesName(values, campaigns, 'id', 'title');
     case 'labels':