Add is_unknown flag in data model for unknown licenses

This reverts commit a1843cf.

Signed-off-by: akugarg <[email protected]>

Author: akugarg

src/licensedcode/data/rules/agpl-3.0_and_other-copyleft_and_unknown_1.yml

@@ -1,6 +1,5 @@
 license_expression: agpl-3.0 AND other-copyleft AND unknown
 is_license_notice: yes
-is_unknown: yes
 relevance: 100
 notes: contains several additions that may or may not be a problem wrt. compatibility with the
     AGPL

src/licensedcode/data/rules/agpl-3.0_and_unknown_1.yml

@@ -1,6 +1,5 @@
 license_expression: agpl-3.0 AND unknown
 is_license_tag: yes
-is_unknown: yes
 relevance: 100
 notes: commercial use right are not clear
 ignorable_urls:

src/licensedcode/data/rules/apache-2.0_and_free-unknown_1.yml

@@ -1,4 +1,3 @@
 license_expression: apache-2.0 AND free-unknown
 is_license_tag: yes
-is_unknown: yes
 relevance: 100

src/licensedcode/data/rules/apache-2.0_and_free-unknown_2.yml

@@ -1,6 +1,5 @@
 license_expression: apache-2.0 AND free-unknown
 is_license_notice: yes
-is_unknown: yes
 minimum_coverage: 80
 referenced_filenames:
     - docs/THIRDPARTY

src/licensedcode/data/rules/apache-2.0_and_free-unknown_zulip.yml

@@ -1,6 +1,5 @@
 license_expression: apache-2.0 AND free-unknown
 is_license_notice: yes
-is_unknown: yes
 minimum_coverage: 80
 referenced_filenames:
     - docs/THIRDPARTY

src/licensedcode/data/rules/apache-2.0_or_free-unknown_1.yml

@@ -1,4 +1,3 @@
 license_expression: apache-2.0 OR free-unknown
 is_license_notice: yes
-is_unknown: yes
 relevance: 100

src/licensedcode/data/rules/apache-2.0_or_free-unknown_2.yml

@@ -1,4 +1,3 @@
 license_expression: apache-2.0 OR free-unknown
 is_license_notice: yes
-is_unknown: yes
 relevance: 100

src/licensedcode/data/rules/apsl-1.2_5.yml

@@ -1,3 +1,2 @@
 license_expression: apsl-1.2 AND unknown
 is_license_reference: yes
-is_unknown: yes

src/licensedcode/data/rules/bsd-simplified_and_bsd-new_and_unknown-license-reference_nuget_url_1.yml

@@ -1,6 +1,5 @@
 license_expression: bsd-simplified AND bsd-new AND unknown-license-reference
 is_license_reference: yes
-is_unknown: yes
 relevance: 90
 ignorable_urls:
     - https://raw.github.com/editorconfig/editorconfig-core/master/LICENSE

src/licensedcode/data/rules/bsd-simplified_and_unknown_1.yml

@@ -1,5 +1,4 @@
 license_expression: bsd-simplified AND unknown
 is_license_notice: yes
-is_unknown: yes
 relevance: 90
 notes: Seen in https://git.icod.de/dalu/i18n