Add separate field in contribution record for Check Number (no uniqueness constraint)

Field should be editable from these "back-office" forms:
Record Contribution
Membership Payment and Receipt block in New / Edit / Renew Membership forms
Payment Information block in New / Edit Event Registration forms

Field s/b displayed in View Contribution page.
Field s/b including in primary export of Contributions.
Field s/b importable.
Field s/b added to Contribution search block.

Update Pending Contribution Status
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The 'Paid By' (payment_instrument_id) and 'Check #' fields also needs to be added to the "Update Pending Contribution Status" functionality since many / most Pay-later payments will be made via check. (CRM/Contribute/Form/Task/Status). For this grid, column order s/b ... Fee, Paid By, Check #, Trxn ID ... Assign class="form-text four" to the Check # input field to keep the grid width from expanding too much.

Add formRule to grid: If Check # is NOT NULL, then Paid By should be "Check". Form Rule msg:
"Paid By should be Check when a check number is entered for a contribution."

(However, we should allow Paid By = "Check" without a Check #. )

Profiles
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Allow users to include the following additional Contribution fields in a Profile (primarily for use in Batch Update via Profile)

• Check Number
• Paid By (e.g. payment_instrument_id) (suppress this for ONLINE contrib profiles)
• Contribution Type (suppress this for ONLINE contrib profiles)