fix: Issues with custom attributes in conversation sidebar (#11476)

# Pull Request Template

## Description

This PR fixes,

1. Fix display issue where the attribute value `0` was not shown for
attributes of type "number" and instead displayed as `"---"`
2. Fix issue where the copy and delete buttons were not visible when the
attribute value was `0`
3. Fix an issue with updating contact custom attributes in the
conversation sidebar (caused by the camelCase param key mismatch in
`contacts/update`; only reproducible for attributes type "date")
4. Ensure the delete button is shown for checkbox-type attributes, even
when the value is `true` or `false` (previously hidden when the value
was `false`, despite the key being present)

Fixes
[CW-4326](https://linear.app/chatwoot/issue/CW-4326/custom-attribute-with-value-0-not-displayed-correctly-in-chatwoot)
https://github.com/chatwoot/chatwoot/issues/11459

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?

### Loom video

https://www.loom.com/share/77257dc09a37452bab7876d1554b8a03?sid=dc5635eb-4fe0-4f39-8da2-036d71649ffc

## 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
- [ ] 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: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/dashboard/routes/dashboard/conversation/customAttributes/CustomAttributes.vue

@@ -80,17 +80,13 @@ const filteredCustomAttributes = computed(() =>
       customAttributes.value,
       attribute.attribute_key
     );
-    const isCheckbox = attribute.attribute_display_type === 'checkbox';
-    const defaultValue = isCheckbox ? false : '';
 
     return {
       ...attribute,
       type: 'custom_attribute',
       key: attribute.attribute_key,
-      // Set value from customAttributes if it exists, otherwise use default value
-      value: hasValue
-        ? customAttributes.value[attribute.attribute_key]
-        : defaultValue,
+      // Set value from customAttributes if it exists, otherwise use ''
+      value: hasValue ? customAttributes.value[attribute.attribute_key] : '',
     };
   })
 );
@@ -215,7 +211,7 @@ const onUpdate = async (key, value) => {
     } else {
       store.dispatch('contacts/update', {
         id: props.contactId,
-        custom_attributes: updatedAttributes,
+        customAttributes: updatedAttributes,
       });
     }
     useAlert(t('CUSTOM_ATTRIBUTES.FORM.UPDATE.SUCCESS'));