Mismatch in singular/plural for many to many relationships

[Kircheneer]

Environment

• Nautobot version: *
• nautobot-plugin-firewall-model version: 0.1.0-beta.2

Proposed Functionality

Single in on one plurality (my preference would be plural) for all many to many fields. Example:

PolicyRule has its many to many fields in singular, while Policy has them in plural.

class PolicyRule(PrimaryModel):
    (...)
    source_user = models.ManyToManyField(to=UserObject, through="SrcUserM2M", related_name="policy_rules")
    source_user_group = models.ManyToManyField(
        to=UserObjectGroup, through="SrcUserGroupM2M", related_name="policy_rules"
    )
    source_address = models.ManyToManyField(to=AddressObject, through="SrcAddrM2M", related_name="source_policy_rules")
    source_address_group = models.ManyToManyField(
        to=AddressObjectGroup, through="SrcAddrGroupM2M", related_name="source_policy_rules"
    )
    source_zone = models.ForeignKey(
        to=Zone, null=True, blank=True, on_delete=models.SET_NULL, related_name="source_policy_rules"
    )
    destination_address = models.ManyToManyField(
        to=AddressObject, through="DestAddrM2M", related_name="destination_policy_rules"
    )
    destination_address_group = models.ManyToManyField(
        to=AddressObjectGroup, through="DestAddrGroupM2M", related_name="destination_policy_rules"
    )
    destination_zone = models.ForeignKey(
        to=Zone, on_delete=models.SET_NULL, null=True, blank=True, related_name="destination_policy_rules"
    )
    service = models.ManyToManyField(to=ServiceObject, through="SvcM2M", related_name="policy_rules")
    service_group = models.ManyToManyField(to=ServiceObjectGroup, through="SvcGroupM2M", related_name="policy_rules")

class Policy(PrimaryModel):
    (...)
    policy_rules = models.ManyToManyField(to=PolicyRule, through="PolicyRuleM2M", related_name="policies")
    assigned_devices = models.ManyToManyField(
        to="dcim.Device", through="PolicyDeviceM2M", related_name="firewall_policies"
    )
    assigned_dynamic_groups = models.ManyToManyField(
        to="extras.DynamicGroup", through="PolicyDynamicGroupM2M", related_name="firewall_policies"
    )

Use Case

Greater level of intuition for field naming.

[whitej6]

Resolved by #80