Add string formats (capitalize, title, upper, and lower)

[MiguelTVMS]

On the formatters add support for string formatters like capitalize, title, upper, and lower this goes on par with the Jinja template filters.

Examples on climate.office_radiator_valve

{{ state_attr('climate.office_radiator_valve', 'hvac_action') }} = idle
{{ state_attr('climate.office_radiator_valve', 'hvac_action') | capitalize }} = Idle

Other Examples

{{ 'title test' | title }} = Title Test
{{ 'uppercase' | upper }} = UPPERCASE
{{ 'LowerCase' | lower }} = lowercase 

Giving us these formatters avoid situations lie this