Add optional support for the CapitalizedCamelCase and CONST_CASE formats

[wscourge]

The CapitalizedCamelCase and CONST_CASE formats could be supported along camelCase, snake_case and the kebab-case formats. All the formats used should be configurable via the extension's settings.

Acceptance Criteria:

• Add package.json["contributes"]["configuration"]["properties"]["togglecase.cases"] array with ["kebabCase", "camelCase", "snakeCase"] defaults; those should all be camelCased for consistent naming in extension's functions namespace
• Add support for differentiating casing by languageId, same as togglecase.pattern
• Implement reading cases from the configuration - order of cases in their array should define the order of toggling
• Create an interface with the correctly defined union for all the cases supported
• CapitalizedCamelCase toggling should not happen for no-case strings, such as for example "email" or "id" (it might upcase them by default)
• Document the new behavior in the README.md#extension-settings section

For CapitalizedCamelCase, the easy approach is to use _.upperFirst(_.camelCase(value)).