fix: allow addition of custom component to dropdown list, added unit …

[azeezat]

Description

1. Allow addition of custom component to dropdown list
2. Added autoCloseOnSelect prop that allows user to prevent dropdown from closing when only one option is selected

Fixes #73 #70

Type of change

Please delete options that are not relevant.

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

How Has This Been Tested?

 <DropdownSelect
            label="Border has been removed"
            placeholder="Select users"
            options={[
              {
                value: '01',
                labelComponent: (
                  <View
                    style={{
                      flexDirection: 'row',
                      justifyContent: 'center',
                      alignItems: 'center',
                    }}>
                    <Image
                      style={styles.avatarStyle}
                      source={{
                        uri: 'https://avatar.iran.liara.run/public/boy?username=Ash',
                      }}
                    />

                    <Text>John Doe</Text>
                  </View>
                ),
              },
              {
                value: '02',
                labelComponent: (
                  <View
                    style={{
                      flexDirection: 'row',
                      justifyContent: 'center',
                      alignItems: 'center',
                    }}>
                    <Image
                      style={styles.avatarStyle}
                      source={{
                        uri: 'https://avatar.iran.liara.run/username?username=Azeezat+Raheem',
                      }}
                    />

                    <Text>James Bond</Text>
                  </View>
                ),
              },
            ]}
            optionLabel={'labelComponent'}
            optionValue={'value'}
            selectedValue={users}
            onValueChange={(itemValue: any) => setUsers(itemValue)}
            isSearchable
          />

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have 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 and published in downstream modules