This basically replaces the (NMMetaTermColor, NMMetaTermFormat) combo
with NMMetaColor that describes the colored element semantically as
opposed to storing the raw attributes.
A (currently static) paletted is used to translate the semantic color
code to the actual ANSI controle sequence. This matches what
terminal-colors.d(5) schemes use, making it convenient to implement
customizable palettes.
When generating output data, nmcli iterates over a list of
property-descriptors (nmc_fields_ip4_config), creates an intermediate
array (output_data) and finally prints it.
However, previously both the meta data (nmc_fields_ip4_config) and
the intermediate format use the same type NmcOutputField. This means,
certain fields are relevant to describe a property, and other fields
are output/formatting fields.
Split this up. Now, the meta data is tracked in form of an NMMetaAbstractInfo
lists. This separates the information about properties from intermediate steps
during creation of the output.
Note that currently functions like print_ip4_config() still have all the
knowledge about how to generate the output. That is wrong, instead, the
meta data (NMMetaAbstractInfo) should describe how to create the output
and then all those functions could be replaced. This means, later we want
to add more knowledge to the NMMetaAbstractInfo, so it is important to
keep them separate from NmcOutputField.
Create a new clients/ subdirectory at the top level, and move cli/ and
tui/ into it, as well as nm-online.c (which was previously in test/,
which made no sense).
cli/ was split into two subdirectories, src/ and completion/. While
this does simplify things (given that the completion file and the
binary both need to be named "nmcli"), it bloats the source tree, and
we can work around it by just renaming the completion file at install
time. Then we can combine the two directories into one and just have
it all under clients/cli/.
