feat: make environment context available (#832)

* feat: make environment context available

This feature adds the "{{.Environment.KubeContext}}" variable.

Discussion #829

Signed-off-by: sewieland <sebastian.wieland@iav.de>

* chore: fix tests which compare logging outputs

This commit adds an addtional space wherever needed to the expected log outputs due to the added "KubeContext" in the environment struct.

Discussion #829

Signed-off-by: Sebastian Wieland <wieland.s@mailbox.org>

* docs: added documentation for `Environment.KubeContext`

Discussion #829

Signed-off-by: Sebastian Wieland <wieland.s@mailbox.org>

* test: make sure the `Environment.KubeContext` is mapped out correctly

Discussion #829

Signed-off-by: Sebastian Wieland <wieland.s@mailbox.org>

---------

Signed-off-by: sewieland <sebastian.wieland@iav.de>
Signed-off-by: Sebastian Wieland <wieland.s@mailbox.org>
Co-authored-by: sewieland <sebastian.wieland@iav.de>

pkg/app/testdata/testreadfromyaml_rendertemplatelog/v0mode/log

@@ -1,5 +1,5 @@
-first-pass rendering starting for "": inherited=&{default map[] map[]}, overrode=<nil>
-first-pass uses: &{default map[] map[]}
+first-pass rendering starting for "": inherited=&{default  map[] map[]}, overrode=<nil>
+first-pass uses: &{default  map[] map[]}
 first-pass rendering output of "":
  0: 
  1: releases:
@@ -9,8 +9,8 @@ first-pass rendering output of "":
  5: 
  6: 
 
-first-pass produced: &{default map[] map[]}
-first-pass rendering result of "": {default map[] map[]}
+first-pass produced: &{default  map[] map[]}
+first-pass rendering result of "": {default  map[] map[]}
 vals:
 map[]
 defaultVals:[]

pkg/app/testdata/testreadfromyaml_rendertemplatelog/v1mode/log

@@ -1,4 +1,4 @@
-rendering starting for "": inherited=&{default map[] map[]}, overrode=<nil>
+rendering starting for "": inherited=&{default  map[] map[]}, overrode=<nil>
 rendering result of "":
  0: 
  1: releases: