Provide ${component} without whitespace of the beginning

[tasshi-me]

Hi there, and thank you for maintaining the great package.

Is your feature request related to a problem? Please describe.

Related to #1623.

I want to use ${component} as the scope of the commit message in pull-request-title-pattern.
e.g. chore(${component}): release ${version}

However the ${component} contains whitespace at the beginning of it.

Describe the solution you'd like

Remove whitespace of ${component}

Describe alternatives you've considered

Provide another template value that represents a component.

Additional context

The whitespace is added in:

release-please/src/util/pull-request-title.ts

Line 159 in 3169b43

const component = this.component ? ` ${this.component}` : '';

and parsed in:

release-please/src/util/pull-request-title.ts

Line 48 in 3169b43

.replace('${component}', ' ?(?<component>[\\w-./]*)?')