Added possibility for = in extra annotations defined in excelparser (#…

…752)

# Description
For each annotation it is now allowed to have = in the string that is
added.

It is tested in the excel2onto test which checks that the created
ontology is correct (small change in one of the annotations there).

## Type of change
<!-- Put an `x` in the box that applies. -->
- [ ] Bug fix.
- [ ] New feature.
- [ ] Documentation update.
- [ ] Test update.

## Checklist
<!-- Put an `x` in the boxes that apply. You can also fill these out
after creating the PR. -->

This checklist can be used as a help for the reviewer.

- [ ] Is the code easy to read and understand?
- [ ] Are comments for humans to read, not computers to disregard?
- [ ] Does a new feature has an accompanying new test (in the CI or unit
testing schemes)?
- [ ] Has the documentation been updated as necessary?
- [ ] Does this close the issue?
- [ ] Is the change limited to the issue?
- [ ] Are errors handled for all outcomes?
- [ ] Does the new feature provide new restrictions on dependencies, and
if so is this documented?

## Comments
<!-- Additional comments here, including clarifications on checklist if
applicable. -->

ontopy/excelparser.py

@@ -808,7 +808,7 @@ def _add_entities(
                     or row["Other annotations"] == "nan"
                 ):
                     for annotation in row["Other annotations"].split(";"):
-                        key, value = annotation.split("=")
+                        key, value = annotation.split("=", 1)
                         entity[key.strip(" ")] = english(value.strip(" "))
 
             remaining_rows.difference_update(added_rows)

tests/test_excelparser/result_ontology/fromexcelonto.ttl

@@ -72,7 +72,7 @@
 
 :EMMO_7c8ba943-15cf-5621-98a3-ed1e7e68fee8 a owl:Class ;
     emmo:EMMO_967080e5_2f42_4eb2_a3a9_c58143e835f9 "A special boundary."@en ;
-    :EMMO_98871837-aa90-5eef-9a56-926ae8beebbb "\"A text about this type of boundary\""@en ;
+    :EMMO_98871837-aa90-5eef-9a56-926ae8beebbb "\"A text about this type of=boundary\""@en ;
     rdfs:subClassOf :EMMO_1b2bfe71-5da9-5c46-b137-be45c3e3f9c3 ;
     skos:prefLabel "SpecialBoundary"@en .