Issue: Custom input components (#3)

client/src/app/posts/post-form/post-form.component.html

client/src/app/shared/button/button.component.html

client/src/app/shared/button/button.component.scss

client/src/app/shared/button/button.component.spec.ts

client/src/app/shared/button/button.component.ts

...t/src/app/shared/number-input/number-input.component.html

...t/src/app/shared/number-input/number-input.component.scss

...rc/app/shared/number-input/number-input.component.spec.ts

client/src/app/shared/number-input/number-input.component.ts

client/src/app/shared/select/select.component.html

client/src/app/shared/select/select.component.scss

client/src/app/shared/select/select.component.spec.ts

client/src/app/shared/select/select.component.ts

client/src/app/shared/shared.module.ts

client/src/app/shared/text-input/text-input.component.html

client/src/app/shared/text-input/text-input.component.scss

client/src/app/shared/text-input/text-input.component.ts