Add feature and fix bug for converter

[tadelesh]

1. remove useless enum
2. refine example file name logic
3. add full support for check name availability
4. change body param name and doc
5. change to use ArmResourceCreateOrReplaceAsync
6. add url type support
7. add number precision support
8. fix default value bug
9. fix readonly and patch model split issues
10. change doc syntax

[azure-pipelines]

You may test this build by running autorest --reset and then either:

---

Add the following CLI flags

Pacakge	Flag	Description
@autorest/core	--version:http://tinyurl.com/ywmt9lgg	For changes to autorest core.
@autorest/modelerfour	--use:http://tinyurl.com/yudedu85	For changes to modelerfour.

Or with all

autorest --version:http://tinyurl.com/ywmt9lgg --use:http://tinyurl.com/yudedu85

---

or use the following in your autorest configuration:

# For changes to autorest core
version: "http://tinyurl.com/ywmt9lgg"

# For changes to modelerfour
use-extension:
  "@autorest/modelerfour": "http://tinyurl.com/yudedu85"

---

If this build is good for you, give this comment a thumbs up. (👍) And you should run `autorest --reset` again once you're finished testing to remove it.

[azure-pipelines]

You may test this build by running autorest --reset and then either:

---

Add the following CLI flags

Pacakge	Flag	Description
@autorest/core	--version:http://tinyurl.com/yq9elc8n	For changes to autorest core.
@autorest/modelerfour	--use:http://tinyurl.com/ymxreazm	For changes to modelerfour.

Or with all

autorest --version:http://tinyurl.com/yq9elc8n --use:http://tinyurl.com/ymxreazm

---

or use the following in your autorest configuration:

# For changes to autorest core
version: "http://tinyurl.com/yq9elc8n"

# For changes to modelerfour
use-extension:
  "@autorest/modelerfour": "http://tinyurl.com/ymxreazm"

---

If this build is good for you, give this comment a thumbs up. (👍) And you should run `autorest --reset` again once you're finished testing to remove it.

[azure-pipelines]

You may test this build by running autorest --reset and then either:

---

Add the following CLI flags

Pacakge	Flag	Description
@autorest/core	--version:http://tinyurl.com/yshd3d8v	For changes to autorest core.
@autorest/modelerfour	--use:http://tinyurl.com/yopupcja	For changes to modelerfour.

Or with all

autorest --version:http://tinyurl.com/yshd3d8v --use:http://tinyurl.com/yopupcja

---

or use the following in your autorest configuration:

# For changes to autorest core
version: "http://tinyurl.com/yshd3d8v"

# For changes to modelerfour
use-extension:
  "@autorest/modelerfour": "http://tinyurl.com/yopupcja"

---

If this build is good for you, give this comment a thumbs up. (👍) And you should run `autorest --reset` again once you're finished testing to remove it.