Move changelog into sros2 package.

* Restructures sros2

Enables addition of new colcon built packages in this repo

* Adds sros2_cmake macros for automatic key setup

* YAML -> XML

* Change version and add Michael as maintainer.

Additionally update build dependencies.

* Remove check now that ros2cli is a build dep.

Putting the changelog in the package directory makes
`catkin_generate_changelog` much happier.

Enables addition of new colcon built packages in this repo

* Add generate permissions security command line

Generate an sros2 yaml permissions file with the permissions of every visible node
on the dds network.

Add custom service security to sros2

Example: run the minimal_publisher_lambda node
Execute: `ros2 security generate_permissions node_policies.yaml`

It will create the following file in the current directory:
```
/minimal_publisher:
  services:
    /minimal_publisher/describe_parameters:
      allows:
      - request
      - reply
      .
      .
      .
  topics:
    /parameter_events:
      allows:
      - publish
      - subscribe
    /topic:
      allows:
      - publish
```

cr https://code.amazon.com/reviews/CR-3943967

* Proposed policy definition changes

Issue: services and actions are not considered in the policy yaml
definition.
Solution: Add ipc types (services and actions)

Issue: access values are strings with p, s, or ps in order. This is not
descriptive and difficult to scale should more permissions become necessary.
Solution: Either change the parsing of the string or change the yaml to
be more flexible and descriptive for users.

The proposed changes include:
* Access value is a list, not a string
* Add ipc types such as actions and services
* Access values are no longer shorthand p or s, but publish/subscribe

Amend policy definition with verbose ROS ipc types

* Adds check to allow "/" or no "/" in permissions file
* Renames policy definition file to markdown

Add security macro for automagically generating public and private keys
for authentication and encryption.

custom macro use
`ros2_secure_node(NODES node_name_1 node_name_2 ...)`

cr https://code.amazon.com/reviews/CR-3517594

Issue: services and actions are not considered in the policy yaml
definition.
Solution: Add ipc types (services and actions)

Issue: access values are strings with p, s, or ps in order. This is not
descriptive and difficult to scale should more permissions become necessary.
Solution: Either change the parsing of the string or change the yaml to
be more flexible and descriptive for users.

The proposed changes include:
* Access value is a list, not a string
* Add ipc types such as actions and services
* Access values are no longer shorthand p or s, but publish/subscribe

Amend policy definition with verbose ROS ipc types

Generate an sros2 yaml permissions file with the permissions of every visible node
on the dds network.

Add custom service security to sros2

Example: run the minimal_publisher_lambda node
Execute: `ros2 security generate_permissions node_policies.yaml`

It will create the following file in the current directory:
```
/minimal_publisher:
  services:
    /minimal_publisher/describe_parameters:
      allows:
      - request
      - reply
      .
      .
      .
  topics:
    /parameter_events:
      allows:
      - publish
      - subscribe
    /topic:
      allows:
      - publish
```

cr https://code.amazon.com/reviews/CR-3943967

Update package maintainer for sros2

Signed-off-by: William Woodall <william@osrfoundation.org>

* raise FileNotFoundError if provided permission file doesn't exist

* raise RuntimeError instead

* back to specific exception in API and raise runtime error from higher level caller

* Update linux wiki leveraging remapping for demo

* remove mentions of Beta3, add note for openssl on Bionic

* macos updates

* Bat syntax highlighting

* Windows updates

* Link to connext security plugin install instructions

* get policy file from master

* Misc tutorial tweaks for windows

`set` instead of `export`
use `bat` for cmd.exe highlighting
Remove trailing backticks
Add note about RANDFILE
Remove -s option from curl

* remove partitions

fix topics/srvices prefixes

* Variable rename

* Simplify topic tag

The double <tag> surprised me at first

* fix wrong indent

* dont add newlines for tags that can have only 1 element

* remove now obsolete todo

* rename variable round 2