Improve routing rules in VS/VSR

[pleshakov]

Proposed changes

This PR improves the routing rules in VirtualServer and
VirtualServerRoute:

Introduce actions: implement actions of the type pass.

Before:

  routes:
  - path: /tea
    upstream: tea

Now:

  - path: /tea
    action:
      pass: tea

Get rid of rules field. Instead, add matches field and Improve conditions - allow conditions to include matched values.

Before:

path: /coffee
rules:
  conditions:
  - cookie: user
  matches:
  - values:
    - john
    upstream: coffee-future
  - values:
    - bob
    upstream: coffee-deprecated
  defaultUpstream: coffee-stable

Now:

path: /coffee
matches:
- conditions:
  - cookie: user
    value: john
  action:
    pass: coffee-future
- conditions:
  - cookie: user
    value: bob
  action:
    pass: coffee-deprecated
action:
  pass: coffee-stable

Improve matches - allow splits in matches.

path: /tea
matches:
- conditions:
  - cookie: user
    value: pro
  splits:
  - weight: 90
    action:
      pass: tea-v1
  - weight: 10
    action:
      pass: tea-v2
action:
  pass: tea-v1

The improvements are not backward compatible.

[damienlog]

Proposed changes

This PR improves the routing rules in VirtualServer and
VirtualServerRoute:

Introduce actions: implement actions of the type pass.

Before:

  routes:
  - path: /tea
    upstream: tea

Now:

  - path: /tea
    action:
      pass: tea

Get rid of rules field. Instead, add matches field and Improve conditions - allow conditions to include matched values.

Before:

path: /coffee
rules:
  conditions:
  - cookie: user
  matches:
  - values:
    - john
    upstream: coffee-future
  - values:
    - bob
    upstream: coffee-deprecated
  defaultUpstream: coffee-stable

Now:

path: /coffee
matches:
- conditions:
  - cookie: user
    value: john
  action:
    pass: coffee-future
- conditions:
  - cookie: user
    value: bob
  action:
    pass: coffee-deprecated
action:
  pass: coffee-stable

Improve matches - allow splits in matches.

path: /tea
matches:
- conditions:
  - cookie: user
    value: pro
  splits:
  - weight: 90
    action:
      pass: tea-v1
  - weight: 10
    action:
      pass: tea-v2
action:
  pass: tea-v1

The improvements are not backward compatible.