res_pjsip: Add 100rel option "peer_supported".

This patch adds a new option to the 100rel parameter for pjsip
endpoints called "peer_supported". When an endpoint with this option
receives an incoming request and the request indicated support for the
100rel extension, then Asterisk will send 1xx responses reliably. If
the request did not indicate 100rel support, Asterisk sends 1xx
responses normally.

ASTERISK-30158

Change-Id: Id6d95ffa8f00dab118e0b386146e99f254f287ad

contrib/ast-db-manage/config/versions/539f68bede2c_add_peer_supported_to_100rel.py

@@ -0,0 +1,57 @@
+"""Add peer_supported to 100rel
+
+Revision ID: 539f68bede2c
+Revises: 9f3692b1654b
+Create Date: 2022-08-10 09:36:16.576049
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '539f68bede2c'
+down_revision = '9f3692b1654b'
+
+from alembic import op
+from sqlalchemy.dialects.postgresql import ENUM
+import sqlalchemy as sa
+
+
+OLD_ENUM = ['no', 'required', 'yes']
+NEW_ENUM = ['no', 'required', 'peer_supported', 'yes']
+
+old_type = sa.Enum(*OLD_ENUM, name='pjsip_100rel_values')
+new_type = sa.Enum(*NEW_ENUM, name='pjsip_100rel_values_v2')
+
+def upgrade():
+    context = op.get_context()
+
+    # Upgrading to this revision WILL clear your directmedia values.
+    if context.bind.dialect.name != 'postgresql':
+        op.alter_column('ps_endpoints', '100rel',
+                        type_=new_type,
+                        existing_type=old_type)
+    else:
+        enum = ENUM(*NEW_ENUM, name='pjsip_100rel_values_v2')
+        enum.create(op.get_bind(), checkfirst=False)
+
+        op.execute('ALTER TABLE ps_endpoints ALTER COLUMN 100rel TYPE'
+                   ' pjsip_100rel_values_v2 USING'
+                   ' 100rel::text::pjsip_100rel_values_v2')
+
+        ENUM(name="pjsip_100rel_values").drop(op.get_bind(), checkfirst=False)
+
+def downgrade():
+    context = op.get_context()
+
+    if context.bind.dialect.name != 'postgresql':
+        op.alter_column('ps_endpoints', '100rel',
+                        type_=old_type,
+                        existing_type=new_type)
+    else:
+        enum = ENUM(*OLD_ENUM, name='pjsip_100rel_values')
+        enum.create(op.get_bind(), checkfirst=False)
+
+        op.execute('ALTER TABLE ps_endpoints ALTER COLUMN 100rel TYPE'
+                   ' pjsip_100rel_values USING'
+                   ' 100rel::text::pjsip_100rel_values')
+
+        ENUM(name="pjsip_100rel_values_v2").drop(op.get_bind(), checkfirst=False)