feat: Add an ability to split contributors gf-462

[perekotypole]

• added a split option to the contributors table and contributors list in project page
• split option is shown only for contributors with more than one git email, and it don't let to split it on backed
• added split modal
• when the form is submitted, a new contributor is created and the selected email is transferred to this contributor

[AnutkaGn]

Change please the name of the file (delete "copy")

[perekotypole]

oh, thanks for noticing

[liza-veis]

let's rename it to gitEmailId instead to avoid confusion, and the same for error message

Suggested change

	emailId: z
	gitEmailId: z

[liza-veis]

Suggested change

	EMAIL_REQUIRED: "Email is required",
	GIT_EMAIL_REQUIRED: "Git email is required.",

[liza-veis]

let's create a more specific constant for this

Suggested change

	if (currentContributor.gitEmails.length <= SINGLE_ITEM) {
	if (currentContributor.gitEmails.length <= MIN_GIT_EMAILS_LENGTH_FOR_SPLIT) {

[liza-veis]

should be split in 3d form

Suggested change

	const splittedEmail = currentContributor.gitEmails.find(
	({ id }) => id === payload.emailId,
	);
	const hasSplittedEmail = splittedEmail !== undefined;
	const splitEmail = currentContributor.gitEmails.find(
	({ id }) => id === payload.emailId,
	);
	const splitEmail = splitEmail !== undefined;

[GvoFor]

In case you choose plural here, then change CONTRIBUTOR_SPLIT_FAILED to plural as well:
"Failed to split contributors." instead of "Failed to split contributor."

or leave CONTRIBUTOR_SPLIT_FAILED without any change, and change this message to "Contributor wes successfully split."

[what1s1ove]

LGTM

[Fjortis]

I think it sounds a little bit unclear, perhaps something like this is better?

The selected contributor will be deleted. You can undo this action later using the split functionality.

[perekotypole]

this message was attached to my ticket, I took it from the task