literal_binds in server_default

[Mike Bayer]

similar to #2742 (9bc9d5c1068be878), let's look into literal_binds for server_default as well. 1.0 for now.

example:

tbl = Table("derp", metadata,
    Column("arr", ARRAY(Text),
                server_default=array(["foo", "bar", "baz"])),
)

[Mike Bayer]

• Literal values within a :class:.DefaultClause, which is invoked when using the :paramref:.Column.server_default parameter, will now be rendered using the "inline" compiler, so that they are rendered as-is, rather than as bound parameters. fixes #3087

→ <<cset 81aa5b376eb8>>